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"""Tests for chebyshev module.
"""
from __future__ import division, absolute_import, print_function
import numpy as np
import numpy.polynomial.chebyshev as cheb
from numpy.polynomial.polynomial import polyval
from numpy.testing import (
assert_almost_equal, assert_raises, assert_equal, assert_,
run_module_suite
)
def trim(x):
return cheb.chebtrim(x, tol=1e-6)
T0 = [1]
T1 = [0, 1]
T2 = [-1, 0, 2]
T3 = [0, -3, 0, 4]
T4 = [1, 0, -8, 0, 8]
T5 = [0, 5, 0, -20, 0, 16]
T6 = [-1, 0, 18, 0, -48, 0, 32]
T7 = [0, -7, 0, 56, 0, -112, 0, 64]
T8 = [1, 0, -32, 0, 160, 0, -256, 0, 128]
T9 = [0, 9, 0, -120, 0, 432, 0, -576, 0, 256]
Tlist = [T0, T1, T2, T3, T4, T5, T6, T7, T8, T9]
class TestPrivate(object):
def test__cseries_to_zseries(self):
for i in range(5):
inp = np.array([2] + [1]*i, np.double)
tgt = np.array([.5]*i + [2] + [.5]*i, np.double)
res = cheb._cseries_to_zseries(inp)
assert_equal(res, tgt)
def test__zseries_to_cseries(self):
for i in range(5):
inp = np.array([.5]*i + [2] + [.5]*i, np.double)
tgt = np.array([2] + [1]*i, np.double)
res = cheb._zseries_to_cseries(inp)
assert_equal(res, tgt)
class TestConstants(object):
def test_chebdomain(self):
assert_equal(cheb.chebdomain, [-1, 1])
def test_chebzero(self):
assert_equal(cheb.chebzero, [0])
def test_chebone(self):
assert_equal(cheb.chebone, [1])
def test_chebx(self):
assert_equal(cheb.chebx, [0, 1])
class TestArithmetic(object):
def test_chebadd(self):
for i in range(5):
for j in range(5):
msg = "At i=%d, j=%d" % (i, j)
tgt = np.zeros(max(i, j) + 1)
tgt[i] += 1
tgt[j] += 1
res = cheb.chebadd([0]*i + [1], [0]*j + [1])
assert_equal(trim(res), trim(tgt), err_msg=msg)
def test_chebsub(self):
for i in range(5):
for j in range(5):
msg = "At i=%d, j=%d" % (i, j)
tgt = np.zeros(max(i, j) + 1)
tgt[i] += 1
tgt[j] -= 1
res = cheb.chebsub([0]*i + [1], [0]*j + [1])
assert_equal(trim(res), trim(tgt), err_msg=msg)
def test_chebmulx(self):
assert_equal(cheb.chebmulx([0]), [0])
assert_equal(cheb.chebmulx([1]), [0, 1])
for i in range(1, 5):
ser = [0]*i + [1]
tgt = [0]*(i - 1) + [.5, 0, .5]
assert_equal(cheb.chebmulx(ser), tgt)
def test_chebmul(self):
for i in range(5):
for j in range(5):
msg = "At i=%d, j=%d" % (i, j)
tgt = np.zeros(i + j + 1)
tgt[i + j] += .5
tgt[abs(i - j)] += .5
res = cheb.chebmul([0]*i + [1], [0]*j + [1])
assert_equal(trim(res), trim(tgt), err_msg=msg)
def test_chebdiv(self):
for i in range(5):
for j in range(5):
msg = "At i=%d, j=%d" % (i, j)
ci = [0]*i + [1]
cj = [0]*j + [1]
tgt = cheb.chebadd(ci, cj)
quo, rem = cheb.chebdiv(tgt, ci)
res = cheb.chebadd(cheb.chebmul(quo, ci), rem)
assert_equal(trim(res), trim(tgt), err_msg=msg)
class TestEvaluation(object):
# coefficients of 1 + 2*x + 3*x**2
c1d = np.array([2.5, 2., 1.5])
c2d = np.einsum('i,j->ij', c1d, c1d)
c3d = np.einsum('i,j,k->ijk', c1d, c1d, c1d)
# some random values in [-1, 1)
x = np.random.random((3, 5))*2 - 1
y = polyval(x, [1., 2., 3.])
def test_chebval(self):
#check empty input
assert_equal(cheb.chebval([], [1]).size, 0)
#check normal input)
x = np.linspace(-1, 1)
y = [polyval(x, c) for c in Tlist]
for i in range(10):
msg = "At i=%d" % i
tgt = y[i]
res = cheb.chebval(x, [0]*i + [1])
assert_almost_equal(res, tgt, err_msg=msg)
#check that shape is preserved
for i in range(3):
dims = [2]*i
x = np.zeros(dims)
assert_equal(cheb.chebval(x, [1]).shape, dims)
assert_equal(cheb.chebval(x, [1, 0]).shape, dims)
assert_equal(cheb.chebval(x, [1, 0, 0]).shape, dims)
def test_chebval2d(self):
x1, x2, x3 = self.x
y1, y2, y3 = self.y
#test exceptions
assert_raises(ValueError, cheb.chebval2d, x1, x2[:2], self.c2d)
#test values
tgt = y1*y2
res = cheb.chebval2d(x1, x2, self.c2d)
assert_almost_equal(res, tgt)
#test shape
z = np.ones((2, 3))
res = cheb.chebval2d(z, z, self.c2d)
assert_(res.shape == (2, 3))
def test_chebval3d(self):
x1, x2, x3 = self.x
y1, y2, y3 = self.y
#test exceptions
assert_raises(ValueError, cheb.chebval3d, x1, x2, x3[:2], self.c3d)
#test values
tgt = y1*y2*y3
res = cheb.chebval3d(x1, x2, x3, self.c3d)
assert_almost_equal(res, tgt)
#test shape
z = np.ones((2, 3))
res = cheb.chebval3d(z, z, z, self.c3d)
assert_(res.shape == (2, 3))
def test_chebgrid2d(self):
x1, x2, x3 = self.x
y1, y2, y3 = self.y
#test values
tgt = np.einsum('i,j->ij', y1, y2)
res = cheb.chebgrid2d(x1, x2, self.c2d)
assert_almost_equal(res, tgt)
#test shape
z = np.ones((2, 3))
res = cheb.chebgrid2d(z, z, self.c2d)
assert_(res.shape == (2, 3)*2)
def test_chebgrid3d(self):
x1, x2, x3 = self.x
y1, y2, y3 = self.y
#test values
tgt = np.einsum('i,j,k->ijk', y1, y2, y3)
res = cheb.chebgrid3d(x1, x2, x3, self.c3d)
assert_almost_equal(res, tgt)
#test shape
z = np.ones((2, 3))
res = cheb.chebgrid3d(z, z, z, self.c3d)
assert_(res.shape == (2, 3)*3)
class TestIntegral(object):
def test_chebint(self):
# check exceptions
assert_raises(ValueError, cheb.chebint, [0], .5)
assert_raises(ValueError, cheb.chebint, [0], -1)
assert_raises(ValueError, cheb.chebint, [0], 1, [0, 0])
assert_raises(ValueError, cheb.chebint, [0], lbnd=[0])
assert_raises(ValueError, cheb.chebint, [0], scl=[0])
assert_raises(ValueError, cheb.chebint, [0], axis=.5)
# test integration of zero polynomial
for i in range(2, 5):
k = [0]*(i - 2) + [1]
res = cheb.chebint([0], m=i, k=k)
assert_almost_equal(res, [0, 1])
# check single integration with integration constant
for i in range(5):
scl = i + 1
pol = [0]*i + [1]
tgt = [i] + [0]*i + [1/scl]
chebpol = cheb.poly2cheb(pol)
chebint = cheb.chebint(chebpol, m=1, k=[i])
res = cheb.cheb2poly(chebint)
assert_almost_equal(trim(res), trim(tgt))
# check single integration with integration constant and lbnd
for i in range(5):
scl = i + 1
pol = [0]*i + [1]
chebpol = cheb.poly2cheb(pol)
chebint = cheb.chebint(chebpol, m=1, k=[i], lbnd=-1)
assert_almost_equal(cheb.chebval(-1, chebint), i)
# check single integration with integration constant and scaling
for i in range(5):
scl = i + 1
pol = [0]*i + [1]
tgt = [i] + [0]*i + [2/scl]
chebpol = cheb.poly2cheb(pol)
chebint = cheb.chebint(chebpol, m=1, k=[i], scl=2)
res = cheb.cheb2poly(chebint)
assert_almost_equal(trim(res), trim(tgt))
# check multiple integrations with default k
for i in range(5):
for j in range(2, 5):
pol = [0]*i + [1]
tgt = pol[:]
for k in range(j):
tgt = cheb.chebint(tgt, m=1)
res = cheb.chebint(pol, m=j)
assert_almost_equal(trim(res), trim(tgt))
# check multiple integrations with defined k
for i in range(5):
for j in range(2, 5):
pol = [0]*i + [1]
tgt = pol[:]
for k in range(j):
tgt = cheb.chebint(tgt, m=1, k=[k])
res = cheb.chebint(pol, m=j, k=list(range(j)))
assert_almost_equal(trim(res), trim(tgt))
# check multiple integrations with lbnd
for i in range(5):
for j in range(2, 5):
pol = [0]*i + [1]
tgt = pol[:]
for k in range(j):
tgt = cheb.chebint(tgt, m=1, k=[k], lbnd=-1)
res = cheb.chebint(pol, m=j, k=list(range(j)), lbnd=-1)
assert_almost_equal(trim(res), trim(tgt))
# check multiple integrations with scaling
for i in range(5):
for j in range(2, 5):
pol = [0]*i + [1]
tgt = pol[:]
for k in range(j):
tgt = cheb.chebint(tgt, m=1, k=[k], scl=2)
res = cheb.chebint(pol, m=j, k=list(range(j)), scl=2)
assert_almost_equal(trim(res), trim(tgt))
def test_chebint_axis(self):
# check that axis keyword works
c2d = np.random.random((3, 4))
tgt = np.vstack([cheb.chebint(c) for c in c2d.T]).T
res = cheb.chebint(c2d, axis=0)
assert_almost_equal(res, tgt)
tgt = np.vstack([cheb.chebint(c) for c in c2d])
res = cheb.chebint(c2d, axis=1)
assert_almost_equal(res, tgt)
tgt = np.vstack([cheb.chebint(c, k=3) for c in c2d])
res = cheb.chebint(c2d, k=3, axis=1)
assert_almost_equal(res, tgt)
class TestDerivative(object):
def test_chebder(self):
# check exceptions
assert_raises(ValueError, cheb.chebder, [0], .5)
assert_raises(ValueError, cheb.chebder, [0], -1)
# check that zeroth derivative does nothing
for i in range(5):
tgt = [0]*i + [1]
res = cheb.chebder(tgt, m=0)
assert_equal(trim(res), trim(tgt))
# check that derivation is the inverse of integration
for i in range(5):
for j in range(2, 5):
tgt = [0]*i + [1]
res = cheb.chebder(cheb.chebint(tgt, m=j), m=j)
assert_almost_equal(trim(res), trim(tgt))
# check derivation with scaling
for i in range(5):
for j in range(2, 5):
tgt = [0]*i + [1]
res = cheb.chebder(cheb.chebint(tgt, m=j, scl=2), m=j, scl=.5)
assert_almost_equal(trim(res), trim(tgt))
def test_chebder_axis(self):
# check that axis keyword works
c2d = np.random.random((3, 4))
tgt = np.vstack([cheb.chebder(c) for c in c2d.T]).T
res = cheb.chebder(c2d, axis=0)
assert_almost_equal(res, tgt)
tgt = np.vstack([cheb.chebder(c) for c in c2d])
res = cheb.chebder(c2d, axis=1)
assert_almost_equal(res, tgt)
class TestVander(object):
# some random values in [-1, 1)
x = np.random.random((3, 5))*2 - 1
def test_chebvander(self):
# check for 1d x
x = np.arange(3)
v = cheb.chebvander(x, 3)
assert_(v.shape == (3, 4))
for i in range(4):
coef = [0]*i + [1]
assert_almost_equal(v[..., i], cheb.chebval(x, coef))
# check for 2d x
x = np.array([[1, 2], [3, 4], [5, 6]])
v = cheb.chebvander(x, 3)
assert_(v.shape == (3, 2, 4))
for i in range(4):
coef = [0]*i + [1]
assert_almost_equal(v[..., i], cheb.chebval(x, coef))
def test_chebvander2d(self):
# also tests chebval2d for non-square coefficient array
x1, x2, x3 = self.x
c = np.random.random((2, 3))
van = cheb.chebvander2d(x1, x2, [1, 2])
tgt = cheb.chebval2d(x1, x2, c)
res = np.dot(van, c.flat)
assert_almost_equal(res, tgt)
# check shape
van = cheb.chebvander2d([x1], [x2], [1, 2])
assert_(van.shape == (1, 5, 6))
def test_chebvander3d(self):
# also tests chebval3d for non-square coefficient array
x1, x2, x3 = self.x
c = np.random.random((2, 3, 4))
van = cheb.chebvander3d(x1, x2, x3, [1, 2, 3])
tgt = cheb.chebval3d(x1, x2, x3, c)
res = np.dot(van, c.flat)
assert_almost_equal(res, tgt)
# check shape
van = cheb.chebvander3d([x1], [x2], [x3], [1, 2, 3])
assert_(van.shape == (1, 5, 24))
class TestFitting(object):
def test_chebfit(self):
def f(x):
return x*(x - 1)*(x - 2)
def f2(x):
return x**4 + x**2 + 1
# Test exceptions
assert_raises(ValueError, cheb.chebfit, [1], [1], -1)
assert_raises(TypeError, cheb.chebfit, [[1]], [1], 0)
assert_raises(TypeError, cheb.chebfit, [], [1], 0)
assert_raises(TypeError, cheb.chebfit, [1], [[[1]]], 0)
assert_raises(TypeError, cheb.chebfit, [1, 2], [1], 0)
assert_raises(TypeError, cheb.chebfit, [1], [1, 2], 0)
assert_raises(TypeError, cheb.chebfit, [1], [1], 0, w=[[1]])
assert_raises(TypeError, cheb.chebfit, [1], [1], 0, w=[1, 1])
assert_raises(ValueError, cheb.chebfit, [1], [1], [-1,])
assert_raises(ValueError, cheb.chebfit, [1], [1], [2, -1, 6])
assert_raises(TypeError, cheb.chebfit, [1], [1], [])
# Test fit
x = np.linspace(0, 2)
y = f(x)
#
coef3 = cheb.chebfit(x, y, 3)
assert_equal(len(coef3), 4)
assert_almost_equal(cheb.chebval(x, coef3), y)
coef3 = cheb.chebfit(x, y, [0, 1, 2, 3])
assert_equal(len(coef3), 4)
assert_almost_equal(cheb.chebval(x, coef3), y)
#
coef4 = cheb.chebfit(x, y, 4)
assert_equal(len(coef4), 5)
assert_almost_equal(cheb.chebval(x, coef4), y)
coef4 = cheb.chebfit(x, y, [0, 1, 2, 3, 4])
assert_equal(len(coef4), 5)
assert_almost_equal(cheb.chebval(x, coef4), y)
# check things still work if deg is not in strict increasing
coef4 = cheb.chebfit(x, y, [2, 3, 4, 1, 0])
assert_equal(len(coef4), 5)
assert_almost_equal(cheb.chebval(x, coef4), y)
#
coef2d = cheb.chebfit(x, np.array([y, y]).T, 3)
assert_almost_equal(coef2d, np.array([coef3, coef3]).T)
coef2d = cheb.chebfit(x, np.array([y, y]).T, [0, 1, 2, 3])
assert_almost_equal(coef2d, np.array([coef3, coef3]).T)
# test weighting
w = np.zeros_like(x)
yw = y.copy()
w[1::2] = 1
y[0::2] = 0
wcoef3 = cheb.chebfit(x, yw, 3, w=w)
assert_almost_equal(wcoef3, coef3)
wcoef3 = cheb.chebfit(x, yw, [0, 1, 2, 3], w=w)
assert_almost_equal(wcoef3, coef3)
#
wcoef2d = cheb.chebfit(x, np.array([yw, yw]).T, 3, w=w)
assert_almost_equal(wcoef2d, np.array([coef3, coef3]).T)
wcoef2d = cheb.chebfit(x, np.array([yw, yw]).T, [0, 1, 2, 3], w=w)
assert_almost_equal(wcoef2d, np.array([coef3, coef3]).T)
# test scaling with complex values x points whose square
# is zero when summed.
x = [1, 1j, -1, -1j]
assert_almost_equal(cheb.chebfit(x, x, 1), [0, 1])
assert_almost_equal(cheb.chebfit(x, x, [0, 1]), [0, 1])
# test fitting only even polynomials
x = np.linspace(-1, 1)
y = f2(x)
coef1 = cheb.chebfit(x, y, 4)
assert_almost_equal(cheb.chebval(x, coef1), y)
coef2 = cheb.chebfit(x, y, [0, 2, 4])
assert_almost_equal(cheb.chebval(x, coef2), y)
assert_almost_equal(coef1, coef2)
class TestInterpolate(object):
def f(self, x):
return x * (x - 1) * (x - 2)
def test_raises(self):
assert_raises(ValueError, cheb.chebinterpolate, self.f, -1)
assert_raises(TypeError, cheb.chebinterpolate, self.f, 10.)
def test_dimensions(self):
for deg in range(1, 5):
assert_(cheb.chebinterpolate(self.f, deg).shape == (deg + 1,))
def test_approximation(self):
def powx(x, p):
return x**p
x = np.linspace(-1, 1, 10)
for deg in range(0, 10):
for p in range(0, deg + 1):
c = cheb.chebinterpolate(powx, deg, (p,))
assert_almost_equal(cheb.chebval(x, c), powx(x, p), decimal=12)
class TestCompanion(object):
def test_raises(self):
assert_raises(ValueError, cheb.chebcompanion, [])
assert_raises(ValueError, cheb.chebcompanion, [1])
def test_dimensions(self):
for i in range(1, 5):
coef = [0]*i + [1]
assert_(cheb.chebcompanion(coef).shape == (i, i))
def test_linear_root(self):
assert_(cheb.chebcompanion([1, 2])[0, 0] == -.5)
class TestGauss(object):
def test_100(self):
x, w = cheb.chebgauss(100)
# test orthogonality. Note that the results need to be normalized,
# otherwise the huge values that can arise from fast growing
# functions like Laguerre can be very confusing.
v = cheb.chebvander(x, 99)
vv = np.dot(v.T * w, v)
vd = 1/np.sqrt(vv.diagonal())
vv = vd[:, None] * vv * vd
assert_almost_equal(vv, np.eye(100))
# check that the integral of 1 is correct
tgt = np.pi
assert_almost_equal(w.sum(), tgt)
class TestMisc(object):
def test_chebfromroots(self):
res = cheb.chebfromroots([])
assert_almost_equal(trim(res), [1])
for i in range(1, 5):
roots = np.cos(np.linspace(-np.pi, 0, 2*i + 1)[1::2])
tgt = [0]*i + [1]
res = cheb.chebfromroots(roots)*2**(i-1)
assert_almost_equal(trim(res), trim(tgt))
def test_chebroots(self):
assert_almost_equal(cheb.chebroots([1]), [])
assert_almost_equal(cheb.chebroots([1, 2]), [-.5])
for i in range(2, 5):
tgt = np.linspace(-1, 1, i)
res = cheb.chebroots(cheb.chebfromroots(tgt))
assert_almost_equal(trim(res), trim(tgt))
def test_chebtrim(self):
coef = [2, -1, 1, 0]
# Test exceptions
assert_raises(ValueError, cheb.chebtrim, coef, -1)
# Test results
assert_equal(cheb.chebtrim(coef), coef[:-1])
assert_equal(cheb.chebtrim(coef, 1), coef[:-3])
assert_equal(cheb.chebtrim(coef, 2), [0])
def test_chebline(self):
assert_equal(cheb.chebline(3, 4), [3, 4])
def test_cheb2poly(self):
for i in range(10):
assert_almost_equal(cheb.cheb2poly([0]*i + [1]), Tlist[i])
def test_poly2cheb(self):
for i in range(10):
assert_almost_equal(cheb.poly2cheb(Tlist[i]), [0]*i + [1])
def test_weight(self):
x = np.linspace(-1, 1, 11)[1:-1]
tgt = 1./(np.sqrt(1 + x) * np.sqrt(1 - x))
res = cheb.chebweight(x)
assert_almost_equal(res, tgt)
def test_chebpts1(self):
#test exceptions
assert_raises(ValueError, cheb.chebpts1, 1.5)
assert_raises(ValueError, cheb.chebpts1, 0)
#test points
tgt = [0]
assert_almost_equal(cheb.chebpts1(1), tgt)
tgt = [-0.70710678118654746, 0.70710678118654746]
assert_almost_equal(cheb.chebpts1(2), tgt)
tgt = [-0.86602540378443871, 0, 0.86602540378443871]
assert_almost_equal(cheb.chebpts1(3), tgt)
tgt = [-0.9238795325, -0.3826834323, 0.3826834323, 0.9238795325]
assert_almost_equal(cheb.chebpts1(4), tgt)
def test_chebpts2(self):
#test exceptions
assert_raises(ValueError, cheb.chebpts2, 1.5)
assert_raises(ValueError, cheb.chebpts2, 1)
#test points
tgt = [-1, 1]
assert_almost_equal(cheb.chebpts2(2), tgt)
tgt = [-1, 0, 1]
assert_almost_equal(cheb.chebpts2(3), tgt)
tgt = [-1, -0.5, .5, 1]
assert_almost_equal(cheb.chebpts2(4), tgt)
tgt = [-1.0, -0.707106781187, 0, 0.707106781187, 1.0]
assert_almost_equal(cheb.chebpts2(5), tgt)
if __name__ == "__main__":
run_module_suite()

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"""Test inter-conversion of different polynomial classes.
This tests the convert and cast methods of all the polynomial classes.
"""
from __future__ import division, absolute_import, print_function
import operator as op
from numbers import Number
import numpy as np
from numpy.polynomial import (
Polynomial, Legendre, Chebyshev, Laguerre, Hermite, HermiteE)
from numpy.testing import (
assert_almost_equal, assert_raises, assert_equal, assert_,
run_module_suite)
from numpy.compat import long
classes = (
Polynomial, Legendre, Chebyshev, Laguerre,
Hermite, HermiteE)
def test_class_methods():
for Poly1 in classes:
for Poly2 in classes:
yield check_conversion, Poly1, Poly2
yield check_cast, Poly1, Poly2
for Poly in classes:
yield check_call, Poly
yield check_identity, Poly
yield check_basis, Poly
yield check_fromroots, Poly
yield check_fit, Poly
yield check_equal, Poly
yield check_not_equal, Poly
yield check_add, Poly
yield check_sub, Poly
yield check_mul, Poly
yield check_floordiv, Poly
yield check_truediv, Poly
yield check_mod, Poly
yield check_divmod, Poly
yield check_pow, Poly
yield check_integ, Poly
yield check_deriv, Poly
yield check_roots, Poly
yield check_linspace, Poly
yield check_mapparms, Poly
yield check_degree, Poly
yield check_copy, Poly
yield check_cutdeg, Poly
yield check_truncate, Poly
yield check_trim, Poly
yield check_ufunc_override, Poly
#
# helper functions
#
random = np.random.random
def assert_poly_almost_equal(p1, p2, msg=""):
try:
assert_(np.all(p1.domain == p2.domain))
assert_(np.all(p1.window == p2.window))
assert_almost_equal(p1.coef, p2.coef)
except AssertionError:
msg = "Result: %s\nTarget: %s", (p1, p2)
raise AssertionError(msg)
#
# conversion methods that depend on two classes
#
def check_conversion(Poly1, Poly2):
x = np.linspace(0, 1, 10)
coef = random((3,))
d1 = Poly1.domain + random((2,))*.25
w1 = Poly1.window + random((2,))*.25
p1 = Poly1(coef, domain=d1, window=w1)
d2 = Poly2.domain + random((2,))*.25
w2 = Poly2.window + random((2,))*.25
p2 = p1.convert(kind=Poly2, domain=d2, window=w2)
assert_almost_equal(p2.domain, d2)
assert_almost_equal(p2.window, w2)
assert_almost_equal(p2(x), p1(x))
def check_cast(Poly1, Poly2):
x = np.linspace(0, 1, 10)
coef = random((3,))
d1 = Poly1.domain + random((2,))*.25
w1 = Poly1.window + random((2,))*.25
p1 = Poly1(coef, domain=d1, window=w1)
d2 = Poly2.domain + random((2,))*.25
w2 = Poly2.window + random((2,))*.25
p2 = Poly2.cast(p1, domain=d2, window=w2)
assert_almost_equal(p2.domain, d2)
assert_almost_equal(p2.window, w2)
assert_almost_equal(p2(x), p1(x))
#
# methods that depend on one class
#
def check_identity(Poly):
d = Poly.domain + random((2,))*.25
w = Poly.window + random((2,))*.25
x = np.linspace(d[0], d[1], 11)
p = Poly.identity(domain=d, window=w)
assert_equal(p.domain, d)
assert_equal(p.window, w)
assert_almost_equal(p(x), x)
def check_basis(Poly):
d = Poly.domain + random((2,))*.25
w = Poly.window + random((2,))*.25
p = Poly.basis(5, domain=d, window=w)
assert_equal(p.domain, d)
assert_equal(p.window, w)
assert_equal(p.coef, [0]*5 + [1])
def check_fromroots(Poly):
# check that requested roots are zeros of a polynomial
# of correct degree, domain, and window.
d = Poly.domain + random((2,))*.25
w = Poly.window + random((2,))*.25
r = random((5,))
p1 = Poly.fromroots(r, domain=d, window=w)
assert_equal(p1.degree(), len(r))
assert_equal(p1.domain, d)
assert_equal(p1.window, w)
assert_almost_equal(p1(r), 0)
# check that polynomial is monic
pdom = Polynomial.domain
pwin = Polynomial.window
p2 = Polynomial.cast(p1, domain=pdom, window=pwin)
assert_almost_equal(p2.coef[-1], 1)
def check_fit(Poly):
def f(x):
return x*(x - 1)*(x - 2)
x = np.linspace(0, 3)
y = f(x)
# check default value of domain and window
p = Poly.fit(x, y, 3)
assert_almost_equal(p.domain, [0, 3])
assert_almost_equal(p(x), y)
assert_equal(p.degree(), 3)
# check with given domains and window
d = Poly.domain + random((2,))*.25
w = Poly.window + random((2,))*.25
p = Poly.fit(x, y, 3, domain=d, window=w)
assert_almost_equal(p(x), y)
assert_almost_equal(p.domain, d)
assert_almost_equal(p.window, w)
p = Poly.fit(x, y, [0, 1, 2, 3], domain=d, window=w)
assert_almost_equal(p(x), y)
assert_almost_equal(p.domain, d)
assert_almost_equal(p.window, w)
# check with class domain default
p = Poly.fit(x, y, 3, [])
assert_equal(p.domain, Poly.domain)
assert_equal(p.window, Poly.window)
p = Poly.fit(x, y, [0, 1, 2, 3], [])
assert_equal(p.domain, Poly.domain)
assert_equal(p.window, Poly.window)
# check that fit accepts weights.
w = np.zeros_like(x)
z = y + random(y.shape)*.25
w[::2] = 1
p1 = Poly.fit(x[::2], z[::2], 3)
p2 = Poly.fit(x, z, 3, w=w)
p3 = Poly.fit(x, z, [0, 1, 2, 3], w=w)
assert_almost_equal(p1(x), p2(x))
assert_almost_equal(p2(x), p3(x))
def check_equal(Poly):
p1 = Poly([1, 2, 3], domain=[0, 1], window=[2, 3])
p2 = Poly([1, 1, 1], domain=[0, 1], window=[2, 3])
p3 = Poly([1, 2, 3], domain=[1, 2], window=[2, 3])
p4 = Poly([1, 2, 3], domain=[0, 1], window=[1, 2])
assert_(p1 == p1)
assert_(not p1 == p2)
assert_(not p1 == p3)
assert_(not p1 == p4)
def check_not_equal(Poly):
p1 = Poly([1, 2, 3], domain=[0, 1], window=[2, 3])
p2 = Poly([1, 1, 1], domain=[0, 1], window=[2, 3])
p3 = Poly([1, 2, 3], domain=[1, 2], window=[2, 3])
p4 = Poly([1, 2, 3], domain=[0, 1], window=[1, 2])
assert_(not p1 != p1)
assert_(p1 != p2)
assert_(p1 != p3)
assert_(p1 != p4)
def check_add(Poly):
# This checks commutation, not numerical correctness
c1 = list(random((4,)) + .5)
c2 = list(random((3,)) + .5)
p1 = Poly(c1)
p2 = Poly(c2)
p3 = p1 + p2
assert_poly_almost_equal(p2 + p1, p3)
assert_poly_almost_equal(p1 + c2, p3)
assert_poly_almost_equal(c2 + p1, p3)
assert_poly_almost_equal(p1 + tuple(c2), p3)
assert_poly_almost_equal(tuple(c2) + p1, p3)
assert_poly_almost_equal(p1 + np.array(c2), p3)
assert_poly_almost_equal(np.array(c2) + p1, p3)
assert_raises(TypeError, op.add, p1, Poly([0], domain=Poly.domain + 1))
assert_raises(TypeError, op.add, p1, Poly([0], window=Poly.window + 1))
if Poly is Polynomial:
assert_raises(TypeError, op.add, p1, Chebyshev([0]))
else:
assert_raises(TypeError, op.add, p1, Polynomial([0]))
def check_sub(Poly):
# This checks commutation, not numerical correctness
c1 = list(random((4,)) + .5)
c2 = list(random((3,)) + .5)
p1 = Poly(c1)
p2 = Poly(c2)
p3 = p1 - p2
assert_poly_almost_equal(p2 - p1, -p3)
assert_poly_almost_equal(p1 - c2, p3)
assert_poly_almost_equal(c2 - p1, -p3)
assert_poly_almost_equal(p1 - tuple(c2), p3)
assert_poly_almost_equal(tuple(c2) - p1, -p3)
assert_poly_almost_equal(p1 - np.array(c2), p3)
assert_poly_almost_equal(np.array(c2) - p1, -p3)
assert_raises(TypeError, op.sub, p1, Poly([0], domain=Poly.domain + 1))
assert_raises(TypeError, op.sub, p1, Poly([0], window=Poly.window + 1))
if Poly is Polynomial:
assert_raises(TypeError, op.sub, p1, Chebyshev([0]))
else:
assert_raises(TypeError, op.sub, p1, Polynomial([0]))
def check_mul(Poly):
c1 = list(random((4,)) + .5)
c2 = list(random((3,)) + .5)
p1 = Poly(c1)
p2 = Poly(c2)
p3 = p1 * p2
assert_poly_almost_equal(p2 * p1, p3)
assert_poly_almost_equal(p1 * c2, p3)
assert_poly_almost_equal(c2 * p1, p3)
assert_poly_almost_equal(p1 * tuple(c2), p3)
assert_poly_almost_equal(tuple(c2) * p1, p3)
assert_poly_almost_equal(p1 * np.array(c2), p3)
assert_poly_almost_equal(np.array(c2) * p1, p3)
assert_poly_almost_equal(p1 * 2, p1 * Poly([2]))
assert_poly_almost_equal(2 * p1, p1 * Poly([2]))
assert_raises(TypeError, op.mul, p1, Poly([0], domain=Poly.domain + 1))
assert_raises(TypeError, op.mul, p1, Poly([0], window=Poly.window + 1))
if Poly is Polynomial:
assert_raises(TypeError, op.mul, p1, Chebyshev([0]))
else:
assert_raises(TypeError, op.mul, p1, Polynomial([0]))
def check_floordiv(Poly):
c1 = list(random((4,)) + .5)
c2 = list(random((3,)) + .5)
c3 = list(random((2,)) + .5)
p1 = Poly(c1)
p2 = Poly(c2)
p3 = Poly(c3)
p4 = p1 * p2 + p3
c4 = list(p4.coef)
assert_poly_almost_equal(p4 // p2, p1)
assert_poly_almost_equal(p4 // c2, p1)
assert_poly_almost_equal(c4 // p2, p1)
assert_poly_almost_equal(p4 // tuple(c2), p1)
assert_poly_almost_equal(tuple(c4) // p2, p1)
assert_poly_almost_equal(p4 // np.array(c2), p1)
assert_poly_almost_equal(np.array(c4) // p2, p1)
assert_poly_almost_equal(2 // p2, Poly([0]))
assert_poly_almost_equal(p2 // 2, 0.5*p2)
assert_raises(
TypeError, op.floordiv, p1, Poly([0], domain=Poly.domain + 1))
assert_raises(
TypeError, op.floordiv, p1, Poly([0], window=Poly.window + 1))
if Poly is Polynomial:
assert_raises(TypeError, op.floordiv, p1, Chebyshev([0]))
else:
assert_raises(TypeError, op.floordiv, p1, Polynomial([0]))
def check_truediv(Poly):
# true division is valid only if the denominator is a Number and
# not a python bool.
p1 = Poly([1,2,3])
p2 = p1 * 5
for stype in np.ScalarType:
if not issubclass(stype, Number) or issubclass(stype, bool):
continue
s = stype(5)
assert_poly_almost_equal(op.truediv(p2, s), p1)
assert_raises(TypeError, op.truediv, s, p2)
for stype in (int, long, float):
s = stype(5)
assert_poly_almost_equal(op.truediv(p2, s), p1)
assert_raises(TypeError, op.truediv, s, p2)
for stype in [complex]:
s = stype(5, 0)
assert_poly_almost_equal(op.truediv(p2, s), p1)
assert_raises(TypeError, op.truediv, s, p2)
for s in [tuple(), list(), dict(), bool(), np.array([1])]:
assert_raises(TypeError, op.truediv, p2, s)
assert_raises(TypeError, op.truediv, s, p2)
for ptype in classes:
assert_raises(TypeError, op.truediv, p2, ptype(1))
def check_mod(Poly):
# This checks commutation, not numerical correctness
c1 = list(random((4,)) + .5)
c2 = list(random((3,)) + .5)
c3 = list(random((2,)) + .5)
p1 = Poly(c1)
p2 = Poly(c2)
p3 = Poly(c3)
p4 = p1 * p2 + p3
c4 = list(p4.coef)
assert_poly_almost_equal(p4 % p2, p3)
assert_poly_almost_equal(p4 % c2, p3)
assert_poly_almost_equal(c4 % p2, p3)
assert_poly_almost_equal(p4 % tuple(c2), p3)
assert_poly_almost_equal(tuple(c4) % p2, p3)
assert_poly_almost_equal(p4 % np.array(c2), p3)
assert_poly_almost_equal(np.array(c4) % p2, p3)
assert_poly_almost_equal(2 % p2, Poly([2]))
assert_poly_almost_equal(p2 % 2, Poly([0]))
assert_raises(TypeError, op.mod, p1, Poly([0], domain=Poly.domain + 1))
assert_raises(TypeError, op.mod, p1, Poly([0], window=Poly.window + 1))
if Poly is Polynomial:
assert_raises(TypeError, op.mod, p1, Chebyshev([0]))
else:
assert_raises(TypeError, op.mod, p1, Polynomial([0]))
def check_divmod(Poly):
# This checks commutation, not numerical correctness
c1 = list(random((4,)) + .5)
c2 = list(random((3,)) + .5)
c3 = list(random((2,)) + .5)
p1 = Poly(c1)
p2 = Poly(c2)
p3 = Poly(c3)
p4 = p1 * p2 + p3
c4 = list(p4.coef)
quo, rem = divmod(p4, p2)
assert_poly_almost_equal(quo, p1)
assert_poly_almost_equal(rem, p3)
quo, rem = divmod(p4, c2)
assert_poly_almost_equal(quo, p1)
assert_poly_almost_equal(rem, p3)
quo, rem = divmod(c4, p2)
assert_poly_almost_equal(quo, p1)
assert_poly_almost_equal(rem, p3)
quo, rem = divmod(p4, tuple(c2))
assert_poly_almost_equal(quo, p1)
assert_poly_almost_equal(rem, p3)
quo, rem = divmod(tuple(c4), p2)
assert_poly_almost_equal(quo, p1)
assert_poly_almost_equal(rem, p3)
quo, rem = divmod(p4, np.array(c2))
assert_poly_almost_equal(quo, p1)
assert_poly_almost_equal(rem, p3)
quo, rem = divmod(np.array(c4), p2)
assert_poly_almost_equal(quo, p1)
assert_poly_almost_equal(rem, p3)
quo, rem = divmod(p2, 2)
assert_poly_almost_equal(quo, 0.5*p2)
assert_poly_almost_equal(rem, Poly([0]))
quo, rem = divmod(2, p2)
assert_poly_almost_equal(quo, Poly([0]))
assert_poly_almost_equal(rem, Poly([2]))
assert_raises(TypeError, divmod, p1, Poly([0], domain=Poly.domain + 1))
assert_raises(TypeError, divmod, p1, Poly([0], window=Poly.window + 1))
if Poly is Polynomial:
assert_raises(TypeError, divmod, p1, Chebyshev([0]))
else:
assert_raises(TypeError, divmod, p1, Polynomial([0]))
def check_roots(Poly):
d = Poly.domain + random((2,))*.25
w = Poly.window + random((2,))*.25
tgt = np.sort(random((5,)))
res = np.sort(Poly.fromroots(tgt, domain=d, window=w).roots())
assert_almost_equal(res, tgt)
# default domain and window
res = np.sort(Poly.fromroots(tgt).roots())
assert_almost_equal(res, tgt)
def check_degree(Poly):
p = Poly.basis(5)
assert_equal(p.degree(), 5)
def check_copy(Poly):
p1 = Poly.basis(5)
p2 = p1.copy()
assert_(p1 == p2)
assert_(p1 is not p2)
assert_(p1.coef is not p2.coef)
assert_(p1.domain is not p2.domain)
assert_(p1.window is not p2.window)
def check_integ(Poly):
P = Polynomial
# Check defaults
p0 = Poly.cast(P([1*2, 2*3, 3*4]))
p1 = P.cast(p0.integ())
p2 = P.cast(p0.integ(2))
assert_poly_almost_equal(p1, P([0, 2, 3, 4]))
assert_poly_almost_equal(p2, P([0, 0, 1, 1, 1]))
# Check with k
p0 = Poly.cast(P([1*2, 2*3, 3*4]))
p1 = P.cast(p0.integ(k=1))
p2 = P.cast(p0.integ(2, k=[1, 1]))
assert_poly_almost_equal(p1, P([1, 2, 3, 4]))
assert_poly_almost_equal(p2, P([1, 1, 1, 1, 1]))
# Check with lbnd
p0 = Poly.cast(P([1*2, 2*3, 3*4]))
p1 = P.cast(p0.integ(lbnd=1))
p2 = P.cast(p0.integ(2, lbnd=1))
assert_poly_almost_equal(p1, P([-9, 2, 3, 4]))
assert_poly_almost_equal(p2, P([6, -9, 1, 1, 1]))
# Check scaling
d = 2*Poly.domain
p0 = Poly.cast(P([1*2, 2*3, 3*4]), domain=d)
p1 = P.cast(p0.integ())
p2 = P.cast(p0.integ(2))
assert_poly_almost_equal(p1, P([0, 2, 3, 4]))
assert_poly_almost_equal(p2, P([0, 0, 1, 1, 1]))
def check_deriv(Poly):
# Check that the derivative is the inverse of integration. It is
# assumes that the integration has been checked elsewhere.
d = Poly.domain + random((2,))*.25
w = Poly.window + random((2,))*.25
p1 = Poly([1, 2, 3], domain=d, window=w)
p2 = p1.integ(2, k=[1, 2])
p3 = p1.integ(1, k=[1])
assert_almost_equal(p2.deriv(1).coef, p3.coef)
assert_almost_equal(p2.deriv(2).coef, p1.coef)
# default domain and window
p1 = Poly([1, 2, 3])
p2 = p1.integ(2, k=[1, 2])
p3 = p1.integ(1, k=[1])
assert_almost_equal(p2.deriv(1).coef, p3.coef)
assert_almost_equal(p2.deriv(2).coef, p1.coef)
def check_linspace(Poly):
d = Poly.domain + random((2,))*.25
w = Poly.window + random((2,))*.25
p = Poly([1, 2, 3], domain=d, window=w)
# check default domain
xtgt = np.linspace(d[0], d[1], 20)
ytgt = p(xtgt)
xres, yres = p.linspace(20)
assert_almost_equal(xres, xtgt)
assert_almost_equal(yres, ytgt)
# check specified domain
xtgt = np.linspace(0, 2, 20)
ytgt = p(xtgt)
xres, yres = p.linspace(20, domain=[0, 2])
assert_almost_equal(xres, xtgt)
assert_almost_equal(yres, ytgt)
def check_pow(Poly):
d = Poly.domain + random((2,))*.25
w = Poly.window + random((2,))*.25
tgt = Poly([1], domain=d, window=w)
tst = Poly([1, 2, 3], domain=d, window=w)
for i in range(5):
assert_poly_almost_equal(tst**i, tgt)
tgt = tgt * tst
# default domain and window
tgt = Poly([1])
tst = Poly([1, 2, 3])
for i in range(5):
assert_poly_almost_equal(tst**i, tgt)
tgt = tgt * tst
# check error for invalid powers
assert_raises(ValueError, op.pow, tgt, 1.5)
assert_raises(ValueError, op.pow, tgt, -1)
def check_call(Poly):
P = Polynomial
d = Poly.domain
x = np.linspace(d[0], d[1], 11)
# Check defaults
p = Poly.cast(P([1, 2, 3]))
tgt = 1 + x*(2 + 3*x)
res = p(x)
assert_almost_equal(res, tgt)
def check_cutdeg(Poly):
p = Poly([1, 2, 3])
assert_raises(ValueError, p.cutdeg, .5)
assert_raises(ValueError, p.cutdeg, -1)
assert_equal(len(p.cutdeg(3)), 3)
assert_equal(len(p.cutdeg(2)), 3)
assert_equal(len(p.cutdeg(1)), 2)
assert_equal(len(p.cutdeg(0)), 1)
def check_truncate(Poly):
p = Poly([1, 2, 3])
assert_raises(ValueError, p.truncate, .5)
assert_raises(ValueError, p.truncate, 0)
assert_equal(len(p.truncate(4)), 3)
assert_equal(len(p.truncate(3)), 3)
assert_equal(len(p.truncate(2)), 2)
assert_equal(len(p.truncate(1)), 1)
def check_trim(Poly):
c = [1, 1e-6, 1e-12, 0]
p = Poly(c)
assert_equal(p.trim().coef, c[:3])
assert_equal(p.trim(1e-10).coef, c[:2])
assert_equal(p.trim(1e-5).coef, c[:1])
def check_mapparms(Poly):
# check with defaults. Should be identity.
d = Poly.domain
w = Poly.window
p = Poly([1], domain=d, window=w)
assert_almost_equal([0, 1], p.mapparms())
#
w = 2*d + 1
p = Poly([1], domain=d, window=w)
assert_almost_equal([1, 2], p.mapparms())
def check_ufunc_override(Poly):
p = Poly([1, 2, 3])
x = np.ones(3)
assert_raises(TypeError, np.add, p, x)
assert_raises(TypeError, np.add, x, p)
class TestInterpolate(object):
def f(self, x):
return x * (x - 1) * (x - 2)
def test_raises(self):
assert_raises(ValueError, Chebyshev.interpolate, self.f, -1)
assert_raises(TypeError, Chebyshev.interpolate, self.f, 10.)
def test_dimensions(self):
for deg in range(1, 5):
assert_(Chebyshev.interpolate(self.f, deg).degree() == deg)
def test_approximation(self):
def powx(x, p):
return x**p
x = np.linspace(0, 2, 10)
for deg in range(0, 10):
for t in range(0, deg + 1):
p = Chebyshev.interpolate(powx, deg, domain=[0, 2], args=(t,))
assert_almost_equal(p(x), powx(x, t), decimal=12)
if __name__ == "__main__":
run_module_suite()

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@@ -0,0 +1,551 @@
"""Tests for hermite module.
"""
from __future__ import division, absolute_import, print_function
import numpy as np
import numpy.polynomial.hermite as herm
from numpy.polynomial.polynomial import polyval
from numpy.testing import (
assert_almost_equal, assert_raises, assert_equal, assert_,
run_module_suite
)
H0 = np.array([1])
H1 = np.array([0, 2])
H2 = np.array([-2, 0, 4])
H3 = np.array([0, -12, 0, 8])
H4 = np.array([12, 0, -48, 0, 16])
H5 = np.array([0, 120, 0, -160, 0, 32])
H6 = np.array([-120, 0, 720, 0, -480, 0, 64])
H7 = np.array([0, -1680, 0, 3360, 0, -1344, 0, 128])
H8 = np.array([1680, 0, -13440, 0, 13440, 0, -3584, 0, 256])
H9 = np.array([0, 30240, 0, -80640, 0, 48384, 0, -9216, 0, 512])
Hlist = [H0, H1, H2, H3, H4, H5, H6, H7, H8, H9]
def trim(x):
return herm.hermtrim(x, tol=1e-6)
class TestConstants(object):
def test_hermdomain(self):
assert_equal(herm.hermdomain, [-1, 1])
def test_hermzero(self):
assert_equal(herm.hermzero, [0])
def test_hermone(self):
assert_equal(herm.hermone, [1])
def test_hermx(self):
assert_equal(herm.hermx, [0, .5])
class TestArithmetic(object):
x = np.linspace(-3, 3, 100)
def test_hermadd(self):
for i in range(5):
for j in range(5):
msg = "At i=%d, j=%d" % (i, j)
tgt = np.zeros(max(i, j) + 1)
tgt[i] += 1
tgt[j] += 1
res = herm.hermadd([0]*i + [1], [0]*j + [1])
assert_equal(trim(res), trim(tgt), err_msg=msg)
def test_hermsub(self):
for i in range(5):
for j in range(5):
msg = "At i=%d, j=%d" % (i, j)
tgt = np.zeros(max(i, j) + 1)
tgt[i] += 1
tgt[j] -= 1
res = herm.hermsub([0]*i + [1], [0]*j + [1])
assert_equal(trim(res), trim(tgt), err_msg=msg)
def test_hermmulx(self):
assert_equal(herm.hermmulx([0]), [0])
assert_equal(herm.hermmulx([1]), [0, .5])
for i in range(1, 5):
ser = [0]*i + [1]
tgt = [0]*(i - 1) + [i, 0, .5]
assert_equal(herm.hermmulx(ser), tgt)
def test_hermmul(self):
# check values of result
for i in range(5):
pol1 = [0]*i + [1]
val1 = herm.hermval(self.x, pol1)
for j in range(5):
msg = "At i=%d, j=%d" % (i, j)
pol2 = [0]*j + [1]
val2 = herm.hermval(self.x, pol2)
pol3 = herm.hermmul(pol1, pol2)
val3 = herm.hermval(self.x, pol3)
assert_(len(pol3) == i + j + 1, msg)
assert_almost_equal(val3, val1*val2, err_msg=msg)
def test_hermdiv(self):
for i in range(5):
for j in range(5):
msg = "At i=%d, j=%d" % (i, j)
ci = [0]*i + [1]
cj = [0]*j + [1]
tgt = herm.hermadd(ci, cj)
quo, rem = herm.hermdiv(tgt, ci)
res = herm.hermadd(herm.hermmul(quo, ci), rem)
assert_equal(trim(res), trim(tgt), err_msg=msg)
class TestEvaluation(object):
# coefficients of 1 + 2*x + 3*x**2
c1d = np.array([2.5, 1., .75])
c2d = np.einsum('i,j->ij', c1d, c1d)
c3d = np.einsum('i,j,k->ijk', c1d, c1d, c1d)
# some random values in [-1, 1)
x = np.random.random((3, 5))*2 - 1
y = polyval(x, [1., 2., 3.])
def test_hermval(self):
#check empty input
assert_equal(herm.hermval([], [1]).size, 0)
#check normal input)
x = np.linspace(-1, 1)
y = [polyval(x, c) for c in Hlist]
for i in range(10):
msg = "At i=%d" % i
tgt = y[i]
res = herm.hermval(x, [0]*i + [1])
assert_almost_equal(res, tgt, err_msg=msg)
#check that shape is preserved
for i in range(3):
dims = [2]*i
x = np.zeros(dims)
assert_equal(herm.hermval(x, [1]).shape, dims)
assert_equal(herm.hermval(x, [1, 0]).shape, dims)
assert_equal(herm.hermval(x, [1, 0, 0]).shape, dims)
def test_hermval2d(self):
x1, x2, x3 = self.x
y1, y2, y3 = self.y
#test exceptions
assert_raises(ValueError, herm.hermval2d, x1, x2[:2], self.c2d)
#test values
tgt = y1*y2
res = herm.hermval2d(x1, x2, self.c2d)
assert_almost_equal(res, tgt)
#test shape
z = np.ones((2, 3))
res = herm.hermval2d(z, z, self.c2d)
assert_(res.shape == (2, 3))
def test_hermval3d(self):
x1, x2, x3 = self.x
y1, y2, y3 = self.y
#test exceptions
assert_raises(ValueError, herm.hermval3d, x1, x2, x3[:2], self.c3d)
#test values
tgt = y1*y2*y3
res = herm.hermval3d(x1, x2, x3, self.c3d)
assert_almost_equal(res, tgt)
#test shape
z = np.ones((2, 3))
res = herm.hermval3d(z, z, z, self.c3d)
assert_(res.shape == (2, 3))
def test_hermgrid2d(self):
x1, x2, x3 = self.x
y1, y2, y3 = self.y
#test values
tgt = np.einsum('i,j->ij', y1, y2)
res = herm.hermgrid2d(x1, x2, self.c2d)
assert_almost_equal(res, tgt)
#test shape
z = np.ones((2, 3))
res = herm.hermgrid2d(z, z, self.c2d)
assert_(res.shape == (2, 3)*2)
def test_hermgrid3d(self):
x1, x2, x3 = self.x
y1, y2, y3 = self.y
#test values
tgt = np.einsum('i,j,k->ijk', y1, y2, y3)
res = herm.hermgrid3d(x1, x2, x3, self.c3d)
assert_almost_equal(res, tgt)
#test shape
z = np.ones((2, 3))
res = herm.hermgrid3d(z, z, z, self.c3d)
assert_(res.shape == (2, 3)*3)
class TestIntegral(object):
def test_hermint(self):
# check exceptions
assert_raises(ValueError, herm.hermint, [0], .5)
assert_raises(ValueError, herm.hermint, [0], -1)
assert_raises(ValueError, herm.hermint, [0], 1, [0, 0])
assert_raises(ValueError, herm.hermint, [0], lbnd=[0])
assert_raises(ValueError, herm.hermint, [0], scl=[0])
assert_raises(ValueError, herm.hermint, [0], axis=.5)
# test integration of zero polynomial
for i in range(2, 5):
k = [0]*(i - 2) + [1]
res = herm.hermint([0], m=i, k=k)
assert_almost_equal(res, [0, .5])
# check single integration with integration constant
for i in range(5):
scl = i + 1
pol = [0]*i + [1]
tgt = [i] + [0]*i + [1/scl]
hermpol = herm.poly2herm(pol)
hermint = herm.hermint(hermpol, m=1, k=[i])
res = herm.herm2poly(hermint)
assert_almost_equal(trim(res), trim(tgt))
# check single integration with integration constant and lbnd
for i in range(5):
scl = i + 1
pol = [0]*i + [1]
hermpol = herm.poly2herm(pol)
hermint = herm.hermint(hermpol, m=1, k=[i], lbnd=-1)
assert_almost_equal(herm.hermval(-1, hermint), i)
# check single integration with integration constant and scaling
for i in range(5):
scl = i + 1
pol = [0]*i + [1]
tgt = [i] + [0]*i + [2/scl]
hermpol = herm.poly2herm(pol)
hermint = herm.hermint(hermpol, m=1, k=[i], scl=2)
res = herm.herm2poly(hermint)
assert_almost_equal(trim(res), trim(tgt))
# check multiple integrations with default k
for i in range(5):
for j in range(2, 5):
pol = [0]*i + [1]
tgt = pol[:]
for k in range(j):
tgt = herm.hermint(tgt, m=1)
res = herm.hermint(pol, m=j)
assert_almost_equal(trim(res), trim(tgt))
# check multiple integrations with defined k
for i in range(5):
for j in range(2, 5):
pol = [0]*i + [1]
tgt = pol[:]
for k in range(j):
tgt = herm.hermint(tgt, m=1, k=[k])
res = herm.hermint(pol, m=j, k=list(range(j)))
assert_almost_equal(trim(res), trim(tgt))
# check multiple integrations with lbnd
for i in range(5):
for j in range(2, 5):
pol = [0]*i + [1]
tgt = pol[:]
for k in range(j):
tgt = herm.hermint(tgt, m=1, k=[k], lbnd=-1)
res = herm.hermint(pol, m=j, k=list(range(j)), lbnd=-1)
assert_almost_equal(trim(res), trim(tgt))
# check multiple integrations with scaling
for i in range(5):
for j in range(2, 5):
pol = [0]*i + [1]
tgt = pol[:]
for k in range(j):
tgt = herm.hermint(tgt, m=1, k=[k], scl=2)
res = herm.hermint(pol, m=j, k=list(range(j)), scl=2)
assert_almost_equal(trim(res), trim(tgt))
def test_hermint_axis(self):
# check that axis keyword works
c2d = np.random.random((3, 4))
tgt = np.vstack([herm.hermint(c) for c in c2d.T]).T
res = herm.hermint(c2d, axis=0)
assert_almost_equal(res, tgt)
tgt = np.vstack([herm.hermint(c) for c in c2d])
res = herm.hermint(c2d, axis=1)
assert_almost_equal(res, tgt)
tgt = np.vstack([herm.hermint(c, k=3) for c in c2d])
res = herm.hermint(c2d, k=3, axis=1)
assert_almost_equal(res, tgt)
class TestDerivative(object):
def test_hermder(self):
# check exceptions
assert_raises(ValueError, herm.hermder, [0], .5)
assert_raises(ValueError, herm.hermder, [0], -1)
# check that zeroth derivative does nothing
for i in range(5):
tgt = [0]*i + [1]
res = herm.hermder(tgt, m=0)
assert_equal(trim(res), trim(tgt))
# check that derivation is the inverse of integration
for i in range(5):
for j in range(2, 5):
tgt = [0]*i + [1]
res = herm.hermder(herm.hermint(tgt, m=j), m=j)
assert_almost_equal(trim(res), trim(tgt))
# check derivation with scaling
for i in range(5):
for j in range(2, 5):
tgt = [0]*i + [1]
res = herm.hermder(herm.hermint(tgt, m=j, scl=2), m=j, scl=.5)
assert_almost_equal(trim(res), trim(tgt))
def test_hermder_axis(self):
# check that axis keyword works
c2d = np.random.random((3, 4))
tgt = np.vstack([herm.hermder(c) for c in c2d.T]).T
res = herm.hermder(c2d, axis=0)
assert_almost_equal(res, tgt)
tgt = np.vstack([herm.hermder(c) for c in c2d])
res = herm.hermder(c2d, axis=1)
assert_almost_equal(res, tgt)
class TestVander(object):
# some random values in [-1, 1)
x = np.random.random((3, 5))*2 - 1
def test_hermvander(self):
# check for 1d x
x = np.arange(3)
v = herm.hermvander(x, 3)
assert_(v.shape == (3, 4))
for i in range(4):
coef = [0]*i + [1]
assert_almost_equal(v[..., i], herm.hermval(x, coef))
# check for 2d x
x = np.array([[1, 2], [3, 4], [5, 6]])
v = herm.hermvander(x, 3)
assert_(v.shape == (3, 2, 4))
for i in range(4):
coef = [0]*i + [1]
assert_almost_equal(v[..., i], herm.hermval(x, coef))
def test_hermvander2d(self):
# also tests hermval2d for non-square coefficient array
x1, x2, x3 = self.x
c = np.random.random((2, 3))
van = herm.hermvander2d(x1, x2, [1, 2])
tgt = herm.hermval2d(x1, x2, c)
res = np.dot(van, c.flat)
assert_almost_equal(res, tgt)
# check shape
van = herm.hermvander2d([x1], [x2], [1, 2])
assert_(van.shape == (1, 5, 6))
def test_hermvander3d(self):
# also tests hermval3d for non-square coefficient array
x1, x2, x3 = self.x
c = np.random.random((2, 3, 4))
van = herm.hermvander3d(x1, x2, x3, [1, 2, 3])
tgt = herm.hermval3d(x1, x2, x3, c)
res = np.dot(van, c.flat)
assert_almost_equal(res, tgt)
# check shape
van = herm.hermvander3d([x1], [x2], [x3], [1, 2, 3])
assert_(van.shape == (1, 5, 24))
class TestFitting(object):
def test_hermfit(self):
def f(x):
return x*(x - 1)*(x - 2)
def f2(x):
return x**4 + x**2 + 1
# Test exceptions
assert_raises(ValueError, herm.hermfit, [1], [1], -1)
assert_raises(TypeError, herm.hermfit, [[1]], [1], 0)
assert_raises(TypeError, herm.hermfit, [], [1], 0)
assert_raises(TypeError, herm.hermfit, [1], [[[1]]], 0)
assert_raises(TypeError, herm.hermfit, [1, 2], [1], 0)
assert_raises(TypeError, herm.hermfit, [1], [1, 2], 0)
assert_raises(TypeError, herm.hermfit, [1], [1], 0, w=[[1]])
assert_raises(TypeError, herm.hermfit, [1], [1], 0, w=[1, 1])
assert_raises(ValueError, herm.hermfit, [1], [1], [-1,])
assert_raises(ValueError, herm.hermfit, [1], [1], [2, -1, 6])
assert_raises(TypeError, herm.hermfit, [1], [1], [])
# Test fit
x = np.linspace(0, 2)
y = f(x)
#
coef3 = herm.hermfit(x, y, 3)
assert_equal(len(coef3), 4)
assert_almost_equal(herm.hermval(x, coef3), y)
coef3 = herm.hermfit(x, y, [0, 1, 2, 3])
assert_equal(len(coef3), 4)
assert_almost_equal(herm.hermval(x, coef3), y)
#
coef4 = herm.hermfit(x, y, 4)
assert_equal(len(coef4), 5)
assert_almost_equal(herm.hermval(x, coef4), y)
coef4 = herm.hermfit(x, y, [0, 1, 2, 3, 4])
assert_equal(len(coef4), 5)
assert_almost_equal(herm.hermval(x, coef4), y)
# check things still work if deg is not in strict increasing
coef4 = herm.hermfit(x, y, [2, 3, 4, 1, 0])
assert_equal(len(coef4), 5)
assert_almost_equal(herm.hermval(x, coef4), y)
#
coef2d = herm.hermfit(x, np.array([y, y]).T, 3)
assert_almost_equal(coef2d, np.array([coef3, coef3]).T)
coef2d = herm.hermfit(x, np.array([y, y]).T, [0, 1, 2, 3])
assert_almost_equal(coef2d, np.array([coef3, coef3]).T)
# test weighting
w = np.zeros_like(x)
yw = y.copy()
w[1::2] = 1
y[0::2] = 0
wcoef3 = herm.hermfit(x, yw, 3, w=w)
assert_almost_equal(wcoef3, coef3)
wcoef3 = herm.hermfit(x, yw, [0, 1, 2, 3], w=w)
assert_almost_equal(wcoef3, coef3)
#
wcoef2d = herm.hermfit(x, np.array([yw, yw]).T, 3, w=w)
assert_almost_equal(wcoef2d, np.array([coef3, coef3]).T)
wcoef2d = herm.hermfit(x, np.array([yw, yw]).T, [0, 1, 2, 3], w=w)
assert_almost_equal(wcoef2d, np.array([coef3, coef3]).T)
# test scaling with complex values x points whose square
# is zero when summed.
x = [1, 1j, -1, -1j]
assert_almost_equal(herm.hermfit(x, x, 1), [0, .5])
assert_almost_equal(herm.hermfit(x, x, [0, 1]), [0, .5])
# test fitting only even Legendre polynomials
x = np.linspace(-1, 1)
y = f2(x)
coef1 = herm.hermfit(x, y, 4)
assert_almost_equal(herm.hermval(x, coef1), y)
coef2 = herm.hermfit(x, y, [0, 2, 4])
assert_almost_equal(herm.hermval(x, coef2), y)
assert_almost_equal(coef1, coef2)
class TestCompanion(object):
def test_raises(self):
assert_raises(ValueError, herm.hermcompanion, [])
assert_raises(ValueError, herm.hermcompanion, [1])
def test_dimensions(self):
for i in range(1, 5):
coef = [0]*i + [1]
assert_(herm.hermcompanion(coef).shape == (i, i))
def test_linear_root(self):
assert_(herm.hermcompanion([1, 2])[0, 0] == -.25)
class TestGauss(object):
def test_100(self):
x, w = herm.hermgauss(100)
# test orthogonality. Note that the results need to be normalized,
# otherwise the huge values that can arise from fast growing
# functions like Laguerre can be very confusing.
v = herm.hermvander(x, 99)
vv = np.dot(v.T * w, v)
vd = 1/np.sqrt(vv.diagonal())
vv = vd[:, None] * vv * vd
assert_almost_equal(vv, np.eye(100))
# check that the integral of 1 is correct
tgt = np.sqrt(np.pi)
assert_almost_equal(w.sum(), tgt)
class TestMisc(object):
def test_hermfromroots(self):
res = herm.hermfromroots([])
assert_almost_equal(trim(res), [1])
for i in range(1, 5):
roots = np.cos(np.linspace(-np.pi, 0, 2*i + 1)[1::2])
pol = herm.hermfromroots(roots)
res = herm.hermval(roots, pol)
tgt = 0
assert_(len(pol) == i + 1)
assert_almost_equal(herm.herm2poly(pol)[-1], 1)
assert_almost_equal(res, tgt)
def test_hermroots(self):
assert_almost_equal(herm.hermroots([1]), [])
assert_almost_equal(herm.hermroots([1, 1]), [-.5])
for i in range(2, 5):
tgt = np.linspace(-1, 1, i)
res = herm.hermroots(herm.hermfromroots(tgt))
assert_almost_equal(trim(res), trim(tgt))
def test_hermtrim(self):
coef = [2, -1, 1, 0]
# Test exceptions
assert_raises(ValueError, herm.hermtrim, coef, -1)
# Test results
assert_equal(herm.hermtrim(coef), coef[:-1])
assert_equal(herm.hermtrim(coef, 1), coef[:-3])
assert_equal(herm.hermtrim(coef, 2), [0])
def test_hermline(self):
assert_equal(herm.hermline(3, 4), [3, 2])
def test_herm2poly(self):
for i in range(10):
assert_almost_equal(herm.herm2poly([0]*i + [1]), Hlist[i])
def test_poly2herm(self):
for i in range(10):
assert_almost_equal(herm.poly2herm(Hlist[i]), [0]*i + [1])
def test_weight(self):
x = np.linspace(-5, 5, 11)
tgt = np.exp(-x**2)
res = herm.hermweight(x)
assert_almost_equal(res, tgt)
if __name__ == "__main__":
run_module_suite()

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"""Tests for hermite_e module.
"""
from __future__ import division, absolute_import, print_function
import numpy as np
import numpy.polynomial.hermite_e as herme
from numpy.polynomial.polynomial import polyval
from numpy.testing import (
assert_almost_equal, assert_raises, assert_equal, assert_,
run_module_suite
)
He0 = np.array([1])
He1 = np.array([0, 1])
He2 = np.array([-1, 0, 1])
He3 = np.array([0, -3, 0, 1])
He4 = np.array([3, 0, -6, 0, 1])
He5 = np.array([0, 15, 0, -10, 0, 1])
He6 = np.array([-15, 0, 45, 0, -15, 0, 1])
He7 = np.array([0, -105, 0, 105, 0, -21, 0, 1])
He8 = np.array([105, 0, -420, 0, 210, 0, -28, 0, 1])
He9 = np.array([0, 945, 0, -1260, 0, 378, 0, -36, 0, 1])
Helist = [He0, He1, He2, He3, He4, He5, He6, He7, He8, He9]
def trim(x):
return herme.hermetrim(x, tol=1e-6)
class TestConstants(object):
def test_hermedomain(self):
assert_equal(herme.hermedomain, [-1, 1])
def test_hermezero(self):
assert_equal(herme.hermezero, [0])
def test_hermeone(self):
assert_equal(herme.hermeone, [1])
def test_hermex(self):
assert_equal(herme.hermex, [0, 1])
class TestArithmetic(object):
x = np.linspace(-3, 3, 100)
def test_hermeadd(self):
for i in range(5):
for j in range(5):
msg = "At i=%d, j=%d" % (i, j)
tgt = np.zeros(max(i, j) + 1)
tgt[i] += 1
tgt[j] += 1
res = herme.hermeadd([0]*i + [1], [0]*j + [1])
assert_equal(trim(res), trim(tgt), err_msg=msg)
def test_hermesub(self):
for i in range(5):
for j in range(5):
msg = "At i=%d, j=%d" % (i, j)
tgt = np.zeros(max(i, j) + 1)
tgt[i] += 1
tgt[j] -= 1
res = herme.hermesub([0]*i + [1], [0]*j + [1])
assert_equal(trim(res), trim(tgt), err_msg=msg)
def test_hermemulx(self):
assert_equal(herme.hermemulx([0]), [0])
assert_equal(herme.hermemulx([1]), [0, 1])
for i in range(1, 5):
ser = [0]*i + [1]
tgt = [0]*(i - 1) + [i, 0, 1]
assert_equal(herme.hermemulx(ser), tgt)
def test_hermemul(self):
# check values of result
for i in range(5):
pol1 = [0]*i + [1]
val1 = herme.hermeval(self.x, pol1)
for j in range(5):
msg = "At i=%d, j=%d" % (i, j)
pol2 = [0]*j + [1]
val2 = herme.hermeval(self.x, pol2)
pol3 = herme.hermemul(pol1, pol2)
val3 = herme.hermeval(self.x, pol3)
assert_(len(pol3) == i + j + 1, msg)
assert_almost_equal(val3, val1*val2, err_msg=msg)
def test_hermediv(self):
for i in range(5):
for j in range(5):
msg = "At i=%d, j=%d" % (i, j)
ci = [0]*i + [1]
cj = [0]*j + [1]
tgt = herme.hermeadd(ci, cj)
quo, rem = herme.hermediv(tgt, ci)
res = herme.hermeadd(herme.hermemul(quo, ci), rem)
assert_equal(trim(res), trim(tgt), err_msg=msg)
class TestEvaluation(object):
# coefficients of 1 + 2*x + 3*x**2
c1d = np.array([4., 2., 3.])
c2d = np.einsum('i,j->ij', c1d, c1d)
c3d = np.einsum('i,j,k->ijk', c1d, c1d, c1d)
# some random values in [-1, 1)
x = np.random.random((3, 5))*2 - 1
y = polyval(x, [1., 2., 3.])
def test_hermeval(self):
#check empty input
assert_equal(herme.hermeval([], [1]).size, 0)
#check normal input)
x = np.linspace(-1, 1)
y = [polyval(x, c) for c in Helist]
for i in range(10):
msg = "At i=%d" % i
tgt = y[i]
res = herme.hermeval(x, [0]*i + [1])
assert_almost_equal(res, tgt, err_msg=msg)
#check that shape is preserved
for i in range(3):
dims = [2]*i
x = np.zeros(dims)
assert_equal(herme.hermeval(x, [1]).shape, dims)
assert_equal(herme.hermeval(x, [1, 0]).shape, dims)
assert_equal(herme.hermeval(x, [1, 0, 0]).shape, dims)
def test_hermeval2d(self):
x1, x2, x3 = self.x
y1, y2, y3 = self.y
#test exceptions
assert_raises(ValueError, herme.hermeval2d, x1, x2[:2], self.c2d)
#test values
tgt = y1*y2
res = herme.hermeval2d(x1, x2, self.c2d)
assert_almost_equal(res, tgt)
#test shape
z = np.ones((2, 3))
res = herme.hermeval2d(z, z, self.c2d)
assert_(res.shape == (2, 3))
def test_hermeval3d(self):
x1, x2, x3 = self.x
y1, y2, y3 = self.y
#test exceptions
assert_raises(ValueError, herme.hermeval3d, x1, x2, x3[:2], self.c3d)
#test values
tgt = y1*y2*y3
res = herme.hermeval3d(x1, x2, x3, self.c3d)
assert_almost_equal(res, tgt)
#test shape
z = np.ones((2, 3))
res = herme.hermeval3d(z, z, z, self.c3d)
assert_(res.shape == (2, 3))
def test_hermegrid2d(self):
x1, x2, x3 = self.x
y1, y2, y3 = self.y
#test values
tgt = np.einsum('i,j->ij', y1, y2)
res = herme.hermegrid2d(x1, x2, self.c2d)
assert_almost_equal(res, tgt)
#test shape
z = np.ones((2, 3))
res = herme.hermegrid2d(z, z, self.c2d)
assert_(res.shape == (2, 3)*2)
def test_hermegrid3d(self):
x1, x2, x3 = self.x
y1, y2, y3 = self.y
#test values
tgt = np.einsum('i,j,k->ijk', y1, y2, y3)
res = herme.hermegrid3d(x1, x2, x3, self.c3d)
assert_almost_equal(res, tgt)
#test shape
z = np.ones((2, 3))
res = herme.hermegrid3d(z, z, z, self.c3d)
assert_(res.shape == (2, 3)*3)
class TestIntegral(object):
def test_hermeint(self):
# check exceptions
assert_raises(ValueError, herme.hermeint, [0], .5)
assert_raises(ValueError, herme.hermeint, [0], -1)
assert_raises(ValueError, herme.hermeint, [0], 1, [0, 0])
assert_raises(ValueError, herme.hermeint, [0], lbnd=[0])
assert_raises(ValueError, herme.hermeint, [0], scl=[0])
assert_raises(ValueError, herme.hermeint, [0], axis=.5)
# test integration of zero polynomial
for i in range(2, 5):
k = [0]*(i - 2) + [1]
res = herme.hermeint([0], m=i, k=k)
assert_almost_equal(res, [0, 1])
# check single integration with integration constant
for i in range(5):
scl = i + 1
pol = [0]*i + [1]
tgt = [i] + [0]*i + [1/scl]
hermepol = herme.poly2herme(pol)
hermeint = herme.hermeint(hermepol, m=1, k=[i])
res = herme.herme2poly(hermeint)
assert_almost_equal(trim(res), trim(tgt))
# check single integration with integration constant and lbnd
for i in range(5):
scl = i + 1
pol = [0]*i + [1]
hermepol = herme.poly2herme(pol)
hermeint = herme.hermeint(hermepol, m=1, k=[i], lbnd=-1)
assert_almost_equal(herme.hermeval(-1, hermeint), i)
# check single integration with integration constant and scaling
for i in range(5):
scl = i + 1
pol = [0]*i + [1]
tgt = [i] + [0]*i + [2/scl]
hermepol = herme.poly2herme(pol)
hermeint = herme.hermeint(hermepol, m=1, k=[i], scl=2)
res = herme.herme2poly(hermeint)
assert_almost_equal(trim(res), trim(tgt))
# check multiple integrations with default k
for i in range(5):
for j in range(2, 5):
pol = [0]*i + [1]
tgt = pol[:]
for k in range(j):
tgt = herme.hermeint(tgt, m=1)
res = herme.hermeint(pol, m=j)
assert_almost_equal(trim(res), trim(tgt))
# check multiple integrations with defined k
for i in range(5):
for j in range(2, 5):
pol = [0]*i + [1]
tgt = pol[:]
for k in range(j):
tgt = herme.hermeint(tgt, m=1, k=[k])
res = herme.hermeint(pol, m=j, k=list(range(j)))
assert_almost_equal(trim(res), trim(tgt))
# check multiple integrations with lbnd
for i in range(5):
for j in range(2, 5):
pol = [0]*i + [1]
tgt = pol[:]
for k in range(j):
tgt = herme.hermeint(tgt, m=1, k=[k], lbnd=-1)
res = herme.hermeint(pol, m=j, k=list(range(j)), lbnd=-1)
assert_almost_equal(trim(res), trim(tgt))
# check multiple integrations with scaling
for i in range(5):
for j in range(2, 5):
pol = [0]*i + [1]
tgt = pol[:]
for k in range(j):
tgt = herme.hermeint(tgt, m=1, k=[k], scl=2)
res = herme.hermeint(pol, m=j, k=list(range(j)), scl=2)
assert_almost_equal(trim(res), trim(tgt))
def test_hermeint_axis(self):
# check that axis keyword works
c2d = np.random.random((3, 4))
tgt = np.vstack([herme.hermeint(c) for c in c2d.T]).T
res = herme.hermeint(c2d, axis=0)
assert_almost_equal(res, tgt)
tgt = np.vstack([herme.hermeint(c) for c in c2d])
res = herme.hermeint(c2d, axis=1)
assert_almost_equal(res, tgt)
tgt = np.vstack([herme.hermeint(c, k=3) for c in c2d])
res = herme.hermeint(c2d, k=3, axis=1)
assert_almost_equal(res, tgt)
class TestDerivative(object):
def test_hermeder(self):
# check exceptions
assert_raises(ValueError, herme.hermeder, [0], .5)
assert_raises(ValueError, herme.hermeder, [0], -1)
# check that zeroth derivative does nothing
for i in range(5):
tgt = [0]*i + [1]
res = herme.hermeder(tgt, m=0)
assert_equal(trim(res), trim(tgt))
# check that derivation is the inverse of integration
for i in range(5):
for j in range(2, 5):
tgt = [0]*i + [1]
res = herme.hermeder(herme.hermeint(tgt, m=j), m=j)
assert_almost_equal(trim(res), trim(tgt))
# check derivation with scaling
for i in range(5):
for j in range(2, 5):
tgt = [0]*i + [1]
res = herme.hermeder(
herme.hermeint(tgt, m=j, scl=2), m=j, scl=.5)
assert_almost_equal(trim(res), trim(tgt))
def test_hermeder_axis(self):
# check that axis keyword works
c2d = np.random.random((3, 4))
tgt = np.vstack([herme.hermeder(c) for c in c2d.T]).T
res = herme.hermeder(c2d, axis=0)
assert_almost_equal(res, tgt)
tgt = np.vstack([herme.hermeder(c) for c in c2d])
res = herme.hermeder(c2d, axis=1)
assert_almost_equal(res, tgt)
class TestVander(object):
# some random values in [-1, 1)
x = np.random.random((3, 5))*2 - 1
def test_hermevander(self):
# check for 1d x
x = np.arange(3)
v = herme.hermevander(x, 3)
assert_(v.shape == (3, 4))
for i in range(4):
coef = [0]*i + [1]
assert_almost_equal(v[..., i], herme.hermeval(x, coef))
# check for 2d x
x = np.array([[1, 2], [3, 4], [5, 6]])
v = herme.hermevander(x, 3)
assert_(v.shape == (3, 2, 4))
for i in range(4):
coef = [0]*i + [1]
assert_almost_equal(v[..., i], herme.hermeval(x, coef))
def test_hermevander2d(self):
# also tests hermeval2d for non-square coefficient array
x1, x2, x3 = self.x
c = np.random.random((2, 3))
van = herme.hermevander2d(x1, x2, [1, 2])
tgt = herme.hermeval2d(x1, x2, c)
res = np.dot(van, c.flat)
assert_almost_equal(res, tgt)
# check shape
van = herme.hermevander2d([x1], [x2], [1, 2])
assert_(van.shape == (1, 5, 6))
def test_hermevander3d(self):
# also tests hermeval3d for non-square coefficient array
x1, x2, x3 = self.x
c = np.random.random((2, 3, 4))
van = herme.hermevander3d(x1, x2, x3, [1, 2, 3])
tgt = herme.hermeval3d(x1, x2, x3, c)
res = np.dot(van, c.flat)
assert_almost_equal(res, tgt)
# check shape
van = herme.hermevander3d([x1], [x2], [x3], [1, 2, 3])
assert_(van.shape == (1, 5, 24))
class TestFitting(object):
def test_hermefit(self):
def f(x):
return x*(x - 1)*(x - 2)
def f2(x):
return x**4 + x**2 + 1
# Test exceptions
assert_raises(ValueError, herme.hermefit, [1], [1], -1)
assert_raises(TypeError, herme.hermefit, [[1]], [1], 0)
assert_raises(TypeError, herme.hermefit, [], [1], 0)
assert_raises(TypeError, herme.hermefit, [1], [[[1]]], 0)
assert_raises(TypeError, herme.hermefit, [1, 2], [1], 0)
assert_raises(TypeError, herme.hermefit, [1], [1, 2], 0)
assert_raises(TypeError, herme.hermefit, [1], [1], 0, w=[[1]])
assert_raises(TypeError, herme.hermefit, [1], [1], 0, w=[1, 1])
assert_raises(ValueError, herme.hermefit, [1], [1], [-1,])
assert_raises(ValueError, herme.hermefit, [1], [1], [2, -1, 6])
assert_raises(TypeError, herme.hermefit, [1], [1], [])
# Test fit
x = np.linspace(0, 2)
y = f(x)
#
coef3 = herme.hermefit(x, y, 3)
assert_equal(len(coef3), 4)
assert_almost_equal(herme.hermeval(x, coef3), y)
coef3 = herme.hermefit(x, y, [0, 1, 2, 3])
assert_equal(len(coef3), 4)
assert_almost_equal(herme.hermeval(x, coef3), y)
#
coef4 = herme.hermefit(x, y, 4)
assert_equal(len(coef4), 5)
assert_almost_equal(herme.hermeval(x, coef4), y)
coef4 = herme.hermefit(x, y, [0, 1, 2, 3, 4])
assert_equal(len(coef4), 5)
assert_almost_equal(herme.hermeval(x, coef4), y)
# check things still work if deg is not in strict increasing
coef4 = herme.hermefit(x, y, [2, 3, 4, 1, 0])
assert_equal(len(coef4), 5)
assert_almost_equal(herme.hermeval(x, coef4), y)
#
coef2d = herme.hermefit(x, np.array([y, y]).T, 3)
assert_almost_equal(coef2d, np.array([coef3, coef3]).T)
coef2d = herme.hermefit(x, np.array([y, y]).T, [0, 1, 2, 3])
assert_almost_equal(coef2d, np.array([coef3, coef3]).T)
# test weighting
w = np.zeros_like(x)
yw = y.copy()
w[1::2] = 1
y[0::2] = 0
wcoef3 = herme.hermefit(x, yw, 3, w=w)
assert_almost_equal(wcoef3, coef3)
wcoef3 = herme.hermefit(x, yw, [0, 1, 2, 3], w=w)
assert_almost_equal(wcoef3, coef3)
#
wcoef2d = herme.hermefit(x, np.array([yw, yw]).T, 3, w=w)
assert_almost_equal(wcoef2d, np.array([coef3, coef3]).T)
wcoef2d = herme.hermefit(x, np.array([yw, yw]).T, [0, 1, 2, 3], w=w)
assert_almost_equal(wcoef2d, np.array([coef3, coef3]).T)
# test scaling with complex values x points whose square
# is zero when summed.
x = [1, 1j, -1, -1j]
assert_almost_equal(herme.hermefit(x, x, 1), [0, 1])
assert_almost_equal(herme.hermefit(x, x, [0, 1]), [0, 1])
# test fitting only even Legendre polynomials
x = np.linspace(-1, 1)
y = f2(x)
coef1 = herme.hermefit(x, y, 4)
assert_almost_equal(herme.hermeval(x, coef1), y)
coef2 = herme.hermefit(x, y, [0, 2, 4])
assert_almost_equal(herme.hermeval(x, coef2), y)
assert_almost_equal(coef1, coef2)
class TestCompanion(object):
def test_raises(self):
assert_raises(ValueError, herme.hermecompanion, [])
assert_raises(ValueError, herme.hermecompanion, [1])
def test_dimensions(self):
for i in range(1, 5):
coef = [0]*i + [1]
assert_(herme.hermecompanion(coef).shape == (i, i))
def test_linear_root(self):
assert_(herme.hermecompanion([1, 2])[0, 0] == -.5)
class TestGauss(object):
def test_100(self):
x, w = herme.hermegauss(100)
# test orthogonality. Note that the results need to be normalized,
# otherwise the huge values that can arise from fast growing
# functions like Laguerre can be very confusing.
v = herme.hermevander(x, 99)
vv = np.dot(v.T * w, v)
vd = 1/np.sqrt(vv.diagonal())
vv = vd[:, None] * vv * vd
assert_almost_equal(vv, np.eye(100))
# check that the integral of 1 is correct
tgt = np.sqrt(2*np.pi)
assert_almost_equal(w.sum(), tgt)
class TestMisc(object):
def test_hermefromroots(self):
res = herme.hermefromroots([])
assert_almost_equal(trim(res), [1])
for i in range(1, 5):
roots = np.cos(np.linspace(-np.pi, 0, 2*i + 1)[1::2])
pol = herme.hermefromroots(roots)
res = herme.hermeval(roots, pol)
tgt = 0
assert_(len(pol) == i + 1)
assert_almost_equal(herme.herme2poly(pol)[-1], 1)
assert_almost_equal(res, tgt)
def test_hermeroots(self):
assert_almost_equal(herme.hermeroots([1]), [])
assert_almost_equal(herme.hermeroots([1, 1]), [-1])
for i in range(2, 5):
tgt = np.linspace(-1, 1, i)
res = herme.hermeroots(herme.hermefromroots(tgt))
assert_almost_equal(trim(res), trim(tgt))
def test_hermetrim(self):
coef = [2, -1, 1, 0]
# Test exceptions
assert_raises(ValueError, herme.hermetrim, coef, -1)
# Test results
assert_equal(herme.hermetrim(coef), coef[:-1])
assert_equal(herme.hermetrim(coef, 1), coef[:-3])
assert_equal(herme.hermetrim(coef, 2), [0])
def test_hermeline(self):
assert_equal(herme.hermeline(3, 4), [3, 4])
def test_herme2poly(self):
for i in range(10):
assert_almost_equal(herme.herme2poly([0]*i + [1]), Helist[i])
def test_poly2herme(self):
for i in range(10):
assert_almost_equal(herme.poly2herme(Helist[i]), [0]*i + [1])
def test_weight(self):
x = np.linspace(-5, 5, 11)
tgt = np.exp(-.5*x**2)
res = herme.hermeweight(x)
assert_almost_equal(res, tgt)
if __name__ == "__main__":
run_module_suite()

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"""Tests for laguerre module.
"""
from __future__ import division, absolute_import, print_function
import numpy as np
import numpy.polynomial.laguerre as lag
from numpy.polynomial.polynomial import polyval
from numpy.testing import (
assert_almost_equal, assert_raises, assert_equal, assert_,
run_module_suite
)
L0 = np.array([1])/1
L1 = np.array([1, -1])/1
L2 = np.array([2, -4, 1])/2
L3 = np.array([6, -18, 9, -1])/6
L4 = np.array([24, -96, 72, -16, 1])/24
L5 = np.array([120, -600, 600, -200, 25, -1])/120
L6 = np.array([720, -4320, 5400, -2400, 450, -36, 1])/720
Llist = [L0, L1, L2, L3, L4, L5, L6]
def trim(x):
return lag.lagtrim(x, tol=1e-6)
class TestConstants(object):
def test_lagdomain(self):
assert_equal(lag.lagdomain, [0, 1])
def test_lagzero(self):
assert_equal(lag.lagzero, [0])
def test_lagone(self):
assert_equal(lag.lagone, [1])
def test_lagx(self):
assert_equal(lag.lagx, [1, -1])
class TestArithmetic(object):
x = np.linspace(-3, 3, 100)
def test_lagadd(self):
for i in range(5):
for j in range(5):
msg = "At i=%d, j=%d" % (i, j)
tgt = np.zeros(max(i, j) + 1)
tgt[i] += 1
tgt[j] += 1
res = lag.lagadd([0]*i + [1], [0]*j + [1])
assert_equal(trim(res), trim(tgt), err_msg=msg)
def test_lagsub(self):
for i in range(5):
for j in range(5):
msg = "At i=%d, j=%d" % (i, j)
tgt = np.zeros(max(i, j) + 1)
tgt[i] += 1
tgt[j] -= 1
res = lag.lagsub([0]*i + [1], [0]*j + [1])
assert_equal(trim(res), trim(tgt), err_msg=msg)
def test_lagmulx(self):
assert_equal(lag.lagmulx([0]), [0])
assert_equal(lag.lagmulx([1]), [1, -1])
for i in range(1, 5):
ser = [0]*i + [1]
tgt = [0]*(i - 1) + [-i, 2*i + 1, -(i + 1)]
assert_almost_equal(lag.lagmulx(ser), tgt)
def test_lagmul(self):
# check values of result
for i in range(5):
pol1 = [0]*i + [1]
val1 = lag.lagval(self.x, pol1)
for j in range(5):
msg = "At i=%d, j=%d" % (i, j)
pol2 = [0]*j + [1]
val2 = lag.lagval(self.x, pol2)
pol3 = lag.lagmul(pol1, pol2)
val3 = lag.lagval(self.x, pol3)
assert_(len(pol3) == i + j + 1, msg)
assert_almost_equal(val3, val1*val2, err_msg=msg)
def test_lagdiv(self):
for i in range(5):
for j in range(5):
msg = "At i=%d, j=%d" % (i, j)
ci = [0]*i + [1]
cj = [0]*j + [1]
tgt = lag.lagadd(ci, cj)
quo, rem = lag.lagdiv(tgt, ci)
res = lag.lagadd(lag.lagmul(quo, ci), rem)
assert_almost_equal(trim(res), trim(tgt), err_msg=msg)
class TestEvaluation(object):
# coefficients of 1 + 2*x + 3*x**2
c1d = np.array([9., -14., 6.])
c2d = np.einsum('i,j->ij', c1d, c1d)
c3d = np.einsum('i,j,k->ijk', c1d, c1d, c1d)
# some random values in [-1, 1)
x = np.random.random((3, 5))*2 - 1
y = polyval(x, [1., 2., 3.])
def test_lagval(self):
#check empty input
assert_equal(lag.lagval([], [1]).size, 0)
#check normal input)
x = np.linspace(-1, 1)
y = [polyval(x, c) for c in Llist]
for i in range(7):
msg = "At i=%d" % i
tgt = y[i]
res = lag.lagval(x, [0]*i + [1])
assert_almost_equal(res, tgt, err_msg=msg)
#check that shape is preserved
for i in range(3):
dims = [2]*i
x = np.zeros(dims)
assert_equal(lag.lagval(x, [1]).shape, dims)
assert_equal(lag.lagval(x, [1, 0]).shape, dims)
assert_equal(lag.lagval(x, [1, 0, 0]).shape, dims)
def test_lagval2d(self):
x1, x2, x3 = self.x
y1, y2, y3 = self.y
#test exceptions
assert_raises(ValueError, lag.lagval2d, x1, x2[:2], self.c2d)
#test values
tgt = y1*y2
res = lag.lagval2d(x1, x2, self.c2d)
assert_almost_equal(res, tgt)
#test shape
z = np.ones((2, 3))
res = lag.lagval2d(z, z, self.c2d)
assert_(res.shape == (2, 3))
def test_lagval3d(self):
x1, x2, x3 = self.x
y1, y2, y3 = self.y
#test exceptions
assert_raises(ValueError, lag.lagval3d, x1, x2, x3[:2], self.c3d)
#test values
tgt = y1*y2*y3
res = lag.lagval3d(x1, x2, x3, self.c3d)
assert_almost_equal(res, tgt)
#test shape
z = np.ones((2, 3))
res = lag.lagval3d(z, z, z, self.c3d)
assert_(res.shape == (2, 3))
def test_laggrid2d(self):
x1, x2, x3 = self.x
y1, y2, y3 = self.y
#test values
tgt = np.einsum('i,j->ij', y1, y2)
res = lag.laggrid2d(x1, x2, self.c2d)
assert_almost_equal(res, tgt)
#test shape
z = np.ones((2, 3))
res = lag.laggrid2d(z, z, self.c2d)
assert_(res.shape == (2, 3)*2)
def test_laggrid3d(self):
x1, x2, x3 = self.x
y1, y2, y3 = self.y
#test values
tgt = np.einsum('i,j,k->ijk', y1, y2, y3)
res = lag.laggrid3d(x1, x2, x3, self.c3d)
assert_almost_equal(res, tgt)
#test shape
z = np.ones((2, 3))
res = lag.laggrid3d(z, z, z, self.c3d)
assert_(res.shape == (2, 3)*3)
class TestIntegral(object):
def test_lagint(self):
# check exceptions
assert_raises(ValueError, lag.lagint, [0], .5)
assert_raises(ValueError, lag.lagint, [0], -1)
assert_raises(ValueError, lag.lagint, [0], 1, [0, 0])
assert_raises(ValueError, lag.lagint, [0], lbnd=[0])
assert_raises(ValueError, lag.lagint, [0], scl=[0])
assert_raises(ValueError, lag.lagint, [0], axis=.5)
# test integration of zero polynomial
for i in range(2, 5):
k = [0]*(i - 2) + [1]
res = lag.lagint([0], m=i, k=k)
assert_almost_equal(res, [1, -1])
# check single integration with integration constant
for i in range(5):
scl = i + 1
pol = [0]*i + [1]
tgt = [i] + [0]*i + [1/scl]
lagpol = lag.poly2lag(pol)
lagint = lag.lagint(lagpol, m=1, k=[i])
res = lag.lag2poly(lagint)
assert_almost_equal(trim(res), trim(tgt))
# check single integration with integration constant and lbnd
for i in range(5):
scl = i + 1
pol = [0]*i + [1]
lagpol = lag.poly2lag(pol)
lagint = lag.lagint(lagpol, m=1, k=[i], lbnd=-1)
assert_almost_equal(lag.lagval(-1, lagint), i)
# check single integration with integration constant and scaling
for i in range(5):
scl = i + 1
pol = [0]*i + [1]
tgt = [i] + [0]*i + [2/scl]
lagpol = lag.poly2lag(pol)
lagint = lag.lagint(lagpol, m=1, k=[i], scl=2)
res = lag.lag2poly(lagint)
assert_almost_equal(trim(res), trim(tgt))
# check multiple integrations with default k
for i in range(5):
for j in range(2, 5):
pol = [0]*i + [1]
tgt = pol[:]
for k in range(j):
tgt = lag.lagint(tgt, m=1)
res = lag.lagint(pol, m=j)
assert_almost_equal(trim(res), trim(tgt))
# check multiple integrations with defined k
for i in range(5):
for j in range(2, 5):
pol = [0]*i + [1]
tgt = pol[:]
for k in range(j):
tgt = lag.lagint(tgt, m=1, k=[k])
res = lag.lagint(pol, m=j, k=list(range(j)))
assert_almost_equal(trim(res), trim(tgt))
# check multiple integrations with lbnd
for i in range(5):
for j in range(2, 5):
pol = [0]*i + [1]
tgt = pol[:]
for k in range(j):
tgt = lag.lagint(tgt, m=1, k=[k], lbnd=-1)
res = lag.lagint(pol, m=j, k=list(range(j)), lbnd=-1)
assert_almost_equal(trim(res), trim(tgt))
# check multiple integrations with scaling
for i in range(5):
for j in range(2, 5):
pol = [0]*i + [1]
tgt = pol[:]
for k in range(j):
tgt = lag.lagint(tgt, m=1, k=[k], scl=2)
res = lag.lagint(pol, m=j, k=list(range(j)), scl=2)
assert_almost_equal(trim(res), trim(tgt))
def test_lagint_axis(self):
# check that axis keyword works
c2d = np.random.random((3, 4))
tgt = np.vstack([lag.lagint(c) for c in c2d.T]).T
res = lag.lagint(c2d, axis=0)
assert_almost_equal(res, tgt)
tgt = np.vstack([lag.lagint(c) for c in c2d])
res = lag.lagint(c2d, axis=1)
assert_almost_equal(res, tgt)
tgt = np.vstack([lag.lagint(c, k=3) for c in c2d])
res = lag.lagint(c2d, k=3, axis=1)
assert_almost_equal(res, tgt)
class TestDerivative(object):
def test_lagder(self):
# check exceptions
assert_raises(ValueError, lag.lagder, [0], .5)
assert_raises(ValueError, lag.lagder, [0], -1)
# check that zeroth derivative does nothing
for i in range(5):
tgt = [0]*i + [1]
res = lag.lagder(tgt, m=0)
assert_equal(trim(res), trim(tgt))
# check that derivation is the inverse of integration
for i in range(5):
for j in range(2, 5):
tgt = [0]*i + [1]
res = lag.lagder(lag.lagint(tgt, m=j), m=j)
assert_almost_equal(trim(res), trim(tgt))
# check derivation with scaling
for i in range(5):
for j in range(2, 5):
tgt = [0]*i + [1]
res = lag.lagder(lag.lagint(tgt, m=j, scl=2), m=j, scl=.5)
assert_almost_equal(trim(res), trim(tgt))
def test_lagder_axis(self):
# check that axis keyword works
c2d = np.random.random((3, 4))
tgt = np.vstack([lag.lagder(c) for c in c2d.T]).T
res = lag.lagder(c2d, axis=0)
assert_almost_equal(res, tgt)
tgt = np.vstack([lag.lagder(c) for c in c2d])
res = lag.lagder(c2d, axis=1)
assert_almost_equal(res, tgt)
class TestVander(object):
# some random values in [-1, 1)
x = np.random.random((3, 5))*2 - 1
def test_lagvander(self):
# check for 1d x
x = np.arange(3)
v = lag.lagvander(x, 3)
assert_(v.shape == (3, 4))
for i in range(4):
coef = [0]*i + [1]
assert_almost_equal(v[..., i], lag.lagval(x, coef))
# check for 2d x
x = np.array([[1, 2], [3, 4], [5, 6]])
v = lag.lagvander(x, 3)
assert_(v.shape == (3, 2, 4))
for i in range(4):
coef = [0]*i + [1]
assert_almost_equal(v[..., i], lag.lagval(x, coef))
def test_lagvander2d(self):
# also tests lagval2d for non-square coefficient array
x1, x2, x3 = self.x
c = np.random.random((2, 3))
van = lag.lagvander2d(x1, x2, [1, 2])
tgt = lag.lagval2d(x1, x2, c)
res = np.dot(van, c.flat)
assert_almost_equal(res, tgt)
# check shape
van = lag.lagvander2d([x1], [x2], [1, 2])
assert_(van.shape == (1, 5, 6))
def test_lagvander3d(self):
# also tests lagval3d for non-square coefficient array
x1, x2, x3 = self.x
c = np.random.random((2, 3, 4))
van = lag.lagvander3d(x1, x2, x3, [1, 2, 3])
tgt = lag.lagval3d(x1, x2, x3, c)
res = np.dot(van, c.flat)
assert_almost_equal(res, tgt)
# check shape
van = lag.lagvander3d([x1], [x2], [x3], [1, 2, 3])
assert_(van.shape == (1, 5, 24))
class TestFitting(object):
def test_lagfit(self):
def f(x):
return x*(x - 1)*(x - 2)
# Test exceptions
assert_raises(ValueError, lag.lagfit, [1], [1], -1)
assert_raises(TypeError, lag.lagfit, [[1]], [1], 0)
assert_raises(TypeError, lag.lagfit, [], [1], 0)
assert_raises(TypeError, lag.lagfit, [1], [[[1]]], 0)
assert_raises(TypeError, lag.lagfit, [1, 2], [1], 0)
assert_raises(TypeError, lag.lagfit, [1], [1, 2], 0)
assert_raises(TypeError, lag.lagfit, [1], [1], 0, w=[[1]])
assert_raises(TypeError, lag.lagfit, [1], [1], 0, w=[1, 1])
assert_raises(ValueError, lag.lagfit, [1], [1], [-1,])
assert_raises(ValueError, lag.lagfit, [1], [1], [2, -1, 6])
assert_raises(TypeError, lag.lagfit, [1], [1], [])
# Test fit
x = np.linspace(0, 2)
y = f(x)
#
coef3 = lag.lagfit(x, y, 3)
assert_equal(len(coef3), 4)
assert_almost_equal(lag.lagval(x, coef3), y)
coef3 = lag.lagfit(x, y, [0, 1, 2, 3])
assert_equal(len(coef3), 4)
assert_almost_equal(lag.lagval(x, coef3), y)
#
coef4 = lag.lagfit(x, y, 4)
assert_equal(len(coef4), 5)
assert_almost_equal(lag.lagval(x, coef4), y)
coef4 = lag.lagfit(x, y, [0, 1, 2, 3, 4])
assert_equal(len(coef4), 5)
assert_almost_equal(lag.lagval(x, coef4), y)
#
coef2d = lag.lagfit(x, np.array([y, y]).T, 3)
assert_almost_equal(coef2d, np.array([coef3, coef3]).T)
coef2d = lag.lagfit(x, np.array([y, y]).T, [0, 1, 2, 3])
assert_almost_equal(coef2d, np.array([coef3, coef3]).T)
# test weighting
w = np.zeros_like(x)
yw = y.copy()
w[1::2] = 1
y[0::2] = 0
wcoef3 = lag.lagfit(x, yw, 3, w=w)
assert_almost_equal(wcoef3, coef3)
wcoef3 = lag.lagfit(x, yw, [0, 1, 2, 3], w=w)
assert_almost_equal(wcoef3, coef3)
#
wcoef2d = lag.lagfit(x, np.array([yw, yw]).T, 3, w=w)
assert_almost_equal(wcoef2d, np.array([coef3, coef3]).T)
wcoef2d = lag.lagfit(x, np.array([yw, yw]).T, [0, 1, 2, 3], w=w)
assert_almost_equal(wcoef2d, np.array([coef3, coef3]).T)
# test scaling with complex values x points whose square
# is zero when summed.
x = [1, 1j, -1, -1j]
assert_almost_equal(lag.lagfit(x, x, 1), [1, -1])
assert_almost_equal(lag.lagfit(x, x, [0, 1]), [1, -1])
class TestCompanion(object):
def test_raises(self):
assert_raises(ValueError, lag.lagcompanion, [])
assert_raises(ValueError, lag.lagcompanion, [1])
def test_dimensions(self):
for i in range(1, 5):
coef = [0]*i + [1]
assert_(lag.lagcompanion(coef).shape == (i, i))
def test_linear_root(self):
assert_(lag.lagcompanion([1, 2])[0, 0] == 1.5)
class TestGauss(object):
def test_100(self):
x, w = lag.laggauss(100)
# test orthogonality. Note that the results need to be normalized,
# otherwise the huge values that can arise from fast growing
# functions like Laguerre can be very confusing.
v = lag.lagvander(x, 99)
vv = np.dot(v.T * w, v)
vd = 1/np.sqrt(vv.diagonal())
vv = vd[:, None] * vv * vd
assert_almost_equal(vv, np.eye(100))
# check that the integral of 1 is correct
tgt = 1.0
assert_almost_equal(w.sum(), tgt)
class TestMisc(object):
def test_lagfromroots(self):
res = lag.lagfromroots([])
assert_almost_equal(trim(res), [1])
for i in range(1, 5):
roots = np.cos(np.linspace(-np.pi, 0, 2*i + 1)[1::2])
pol = lag.lagfromroots(roots)
res = lag.lagval(roots, pol)
tgt = 0
assert_(len(pol) == i + 1)
assert_almost_equal(lag.lag2poly(pol)[-1], 1)
assert_almost_equal(res, tgt)
def test_lagroots(self):
assert_almost_equal(lag.lagroots([1]), [])
assert_almost_equal(lag.lagroots([0, 1]), [1])
for i in range(2, 5):
tgt = np.linspace(0, 3, i)
res = lag.lagroots(lag.lagfromroots(tgt))
assert_almost_equal(trim(res), trim(tgt))
def test_lagtrim(self):
coef = [2, -1, 1, 0]
# Test exceptions
assert_raises(ValueError, lag.lagtrim, coef, -1)
# Test results
assert_equal(lag.lagtrim(coef), coef[:-1])
assert_equal(lag.lagtrim(coef, 1), coef[:-3])
assert_equal(lag.lagtrim(coef, 2), [0])
def test_lagline(self):
assert_equal(lag.lagline(3, 4), [7, -4])
def test_lag2poly(self):
for i in range(7):
assert_almost_equal(lag.lag2poly([0]*i + [1]), Llist[i])
def test_poly2lag(self):
for i in range(7):
assert_almost_equal(lag.poly2lag(Llist[i]), [0]*i + [1])
def test_weight(self):
x = np.linspace(0, 10, 11)
tgt = np.exp(-x)
res = lag.lagweight(x)
assert_almost_equal(res, tgt)
if __name__ == "__main__":
run_module_suite()

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"""Tests for legendre module.
"""
from __future__ import division, absolute_import, print_function
import numpy as np
import numpy.polynomial.legendre as leg
from numpy.polynomial.polynomial import polyval
from numpy.testing import (
assert_almost_equal, assert_raises, assert_equal, assert_,
run_module_suite
)
L0 = np.array([1])
L1 = np.array([0, 1])
L2 = np.array([-1, 0, 3])/2
L3 = np.array([0, -3, 0, 5])/2
L4 = np.array([3, 0, -30, 0, 35])/8
L5 = np.array([0, 15, 0, -70, 0, 63])/8
L6 = np.array([-5, 0, 105, 0, -315, 0, 231])/16
L7 = np.array([0, -35, 0, 315, 0, -693, 0, 429])/16
L8 = np.array([35, 0, -1260, 0, 6930, 0, -12012, 0, 6435])/128
L9 = np.array([0, 315, 0, -4620, 0, 18018, 0, -25740, 0, 12155])/128
Llist = [L0, L1, L2, L3, L4, L5, L6, L7, L8, L9]
def trim(x):
return leg.legtrim(x, tol=1e-6)
class TestConstants(object):
def test_legdomain(self):
assert_equal(leg.legdomain, [-1, 1])
def test_legzero(self):
assert_equal(leg.legzero, [0])
def test_legone(self):
assert_equal(leg.legone, [1])
def test_legx(self):
assert_equal(leg.legx, [0, 1])
class TestArithmetic(object):
x = np.linspace(-1, 1, 100)
def test_legadd(self):
for i in range(5):
for j in range(5):
msg = "At i=%d, j=%d" % (i, j)
tgt = np.zeros(max(i, j) + 1)
tgt[i] += 1
tgt[j] += 1
res = leg.legadd([0]*i + [1], [0]*j + [1])
assert_equal(trim(res), trim(tgt), err_msg=msg)
def test_legsub(self):
for i in range(5):
for j in range(5):
msg = "At i=%d, j=%d" % (i, j)
tgt = np.zeros(max(i, j) + 1)
tgt[i] += 1
tgt[j] -= 1
res = leg.legsub([0]*i + [1], [0]*j + [1])
assert_equal(trim(res), trim(tgt), err_msg=msg)
def test_legmulx(self):
assert_equal(leg.legmulx([0]), [0])
assert_equal(leg.legmulx([1]), [0, 1])
for i in range(1, 5):
tmp = 2*i + 1
ser = [0]*i + [1]
tgt = [0]*(i - 1) + [i/tmp, 0, (i + 1)/tmp]
assert_equal(leg.legmulx(ser), tgt)
def test_legmul(self):
# check values of result
for i in range(5):
pol1 = [0]*i + [1]
val1 = leg.legval(self.x, pol1)
for j in range(5):
msg = "At i=%d, j=%d" % (i, j)
pol2 = [0]*j + [1]
val2 = leg.legval(self.x, pol2)
pol3 = leg.legmul(pol1, pol2)
val3 = leg.legval(self.x, pol3)
assert_(len(pol3) == i + j + 1, msg)
assert_almost_equal(val3, val1*val2, err_msg=msg)
def test_legdiv(self):
for i in range(5):
for j in range(5):
msg = "At i=%d, j=%d" % (i, j)
ci = [0]*i + [1]
cj = [0]*j + [1]
tgt = leg.legadd(ci, cj)
quo, rem = leg.legdiv(tgt, ci)
res = leg.legadd(leg.legmul(quo, ci), rem)
assert_equal(trim(res), trim(tgt), err_msg=msg)
class TestEvaluation(object):
# coefficients of 1 + 2*x + 3*x**2
c1d = np.array([2., 2., 2.])
c2d = np.einsum('i,j->ij', c1d, c1d)
c3d = np.einsum('i,j,k->ijk', c1d, c1d, c1d)
# some random values in [-1, 1)
x = np.random.random((3, 5))*2 - 1
y = polyval(x, [1., 2., 3.])
def test_legval(self):
#check empty input
assert_equal(leg.legval([], [1]).size, 0)
#check normal input)
x = np.linspace(-1, 1)
y = [polyval(x, c) for c in Llist]
for i in range(10):
msg = "At i=%d" % i
tgt = y[i]
res = leg.legval(x, [0]*i + [1])
assert_almost_equal(res, tgt, err_msg=msg)
#check that shape is preserved
for i in range(3):
dims = [2]*i
x = np.zeros(dims)
assert_equal(leg.legval(x, [1]).shape, dims)
assert_equal(leg.legval(x, [1, 0]).shape, dims)
assert_equal(leg.legval(x, [1, 0, 0]).shape, dims)
def test_legval2d(self):
x1, x2, x3 = self.x
y1, y2, y3 = self.y
#test exceptions
assert_raises(ValueError, leg.legval2d, x1, x2[:2], self.c2d)
#test values
tgt = y1*y2
res = leg.legval2d(x1, x2, self.c2d)
assert_almost_equal(res, tgt)
#test shape
z = np.ones((2, 3))
res = leg.legval2d(z, z, self.c2d)
assert_(res.shape == (2, 3))
def test_legval3d(self):
x1, x2, x3 = self.x
y1, y2, y3 = self.y
#test exceptions
assert_raises(ValueError, leg.legval3d, x1, x2, x3[:2], self.c3d)
#test values
tgt = y1*y2*y3
res = leg.legval3d(x1, x2, x3, self.c3d)
assert_almost_equal(res, tgt)
#test shape
z = np.ones((2, 3))
res = leg.legval3d(z, z, z, self.c3d)
assert_(res.shape == (2, 3))
def test_leggrid2d(self):
x1, x2, x3 = self.x
y1, y2, y3 = self.y
#test values
tgt = np.einsum('i,j->ij', y1, y2)
res = leg.leggrid2d(x1, x2, self.c2d)
assert_almost_equal(res, tgt)
#test shape
z = np.ones((2, 3))
res = leg.leggrid2d(z, z, self.c2d)
assert_(res.shape == (2, 3)*2)
def test_leggrid3d(self):
x1, x2, x3 = self.x
y1, y2, y3 = self.y
#test values
tgt = np.einsum('i,j,k->ijk', y1, y2, y3)
res = leg.leggrid3d(x1, x2, x3, self.c3d)
assert_almost_equal(res, tgt)
#test shape
z = np.ones((2, 3))
res = leg.leggrid3d(z, z, z, self.c3d)
assert_(res.shape == (2, 3)*3)
class TestIntegral(object):
def test_legint(self):
# check exceptions
assert_raises(ValueError, leg.legint, [0], .5)
assert_raises(ValueError, leg.legint, [0], -1)
assert_raises(ValueError, leg.legint, [0], 1, [0, 0])
assert_raises(ValueError, leg.legint, [0], lbnd=[0])
assert_raises(ValueError, leg.legint, [0], scl=[0])
assert_raises(ValueError, leg.legint, [0], axis=.5)
# test integration of zero polynomial
for i in range(2, 5):
k = [0]*(i - 2) + [1]
res = leg.legint([0], m=i, k=k)
assert_almost_equal(res, [0, 1])
# check single integration with integration constant
for i in range(5):
scl = i + 1
pol = [0]*i + [1]
tgt = [i] + [0]*i + [1/scl]
legpol = leg.poly2leg(pol)
legint = leg.legint(legpol, m=1, k=[i])
res = leg.leg2poly(legint)
assert_almost_equal(trim(res), trim(tgt))
# check single integration with integration constant and lbnd
for i in range(5):
scl = i + 1
pol = [0]*i + [1]
legpol = leg.poly2leg(pol)
legint = leg.legint(legpol, m=1, k=[i], lbnd=-1)
assert_almost_equal(leg.legval(-1, legint), i)
# check single integration with integration constant and scaling
for i in range(5):
scl = i + 1
pol = [0]*i + [1]
tgt = [i] + [0]*i + [2/scl]
legpol = leg.poly2leg(pol)
legint = leg.legint(legpol, m=1, k=[i], scl=2)
res = leg.leg2poly(legint)
assert_almost_equal(trim(res), trim(tgt))
# check multiple integrations with default k
for i in range(5):
for j in range(2, 5):
pol = [0]*i + [1]
tgt = pol[:]
for k in range(j):
tgt = leg.legint(tgt, m=1)
res = leg.legint(pol, m=j)
assert_almost_equal(trim(res), trim(tgt))
# check multiple integrations with defined k
for i in range(5):
for j in range(2, 5):
pol = [0]*i + [1]
tgt = pol[:]
for k in range(j):
tgt = leg.legint(tgt, m=1, k=[k])
res = leg.legint(pol, m=j, k=list(range(j)))
assert_almost_equal(trim(res), trim(tgt))
# check multiple integrations with lbnd
for i in range(5):
for j in range(2, 5):
pol = [0]*i + [1]
tgt = pol[:]
for k in range(j):
tgt = leg.legint(tgt, m=1, k=[k], lbnd=-1)
res = leg.legint(pol, m=j, k=list(range(j)), lbnd=-1)
assert_almost_equal(trim(res), trim(tgt))
# check multiple integrations with scaling
for i in range(5):
for j in range(2, 5):
pol = [0]*i + [1]
tgt = pol[:]
for k in range(j):
tgt = leg.legint(tgt, m=1, k=[k], scl=2)
res = leg.legint(pol, m=j, k=list(range(j)), scl=2)
assert_almost_equal(trim(res), trim(tgt))
def test_legint_axis(self):
# check that axis keyword works
c2d = np.random.random((3, 4))
tgt = np.vstack([leg.legint(c) for c in c2d.T]).T
res = leg.legint(c2d, axis=0)
assert_almost_equal(res, tgt)
tgt = np.vstack([leg.legint(c) for c in c2d])
res = leg.legint(c2d, axis=1)
assert_almost_equal(res, tgt)
tgt = np.vstack([leg.legint(c, k=3) for c in c2d])
res = leg.legint(c2d, k=3, axis=1)
assert_almost_equal(res, tgt)
class TestDerivative(object):
def test_legder(self):
# check exceptions
assert_raises(ValueError, leg.legder, [0], .5)
assert_raises(ValueError, leg.legder, [0], -1)
# check that zeroth derivative does nothing
for i in range(5):
tgt = [0]*i + [1]
res = leg.legder(tgt, m=0)
assert_equal(trim(res), trim(tgt))
# check that derivation is the inverse of integration
for i in range(5):
for j in range(2, 5):
tgt = [0]*i + [1]
res = leg.legder(leg.legint(tgt, m=j), m=j)
assert_almost_equal(trim(res), trim(tgt))
# check derivation with scaling
for i in range(5):
for j in range(2, 5):
tgt = [0]*i + [1]
res = leg.legder(leg.legint(tgt, m=j, scl=2), m=j, scl=.5)
assert_almost_equal(trim(res), trim(tgt))
def test_legder_axis(self):
# check that axis keyword works
c2d = np.random.random((3, 4))
tgt = np.vstack([leg.legder(c) for c in c2d.T]).T
res = leg.legder(c2d, axis=0)
assert_almost_equal(res, tgt)
tgt = np.vstack([leg.legder(c) for c in c2d])
res = leg.legder(c2d, axis=1)
assert_almost_equal(res, tgt)
class TestVander(object):
# some random values in [-1, 1)
x = np.random.random((3, 5))*2 - 1
def test_legvander(self):
# check for 1d x
x = np.arange(3)
v = leg.legvander(x, 3)
assert_(v.shape == (3, 4))
for i in range(4):
coef = [0]*i + [1]
assert_almost_equal(v[..., i], leg.legval(x, coef))
# check for 2d x
x = np.array([[1, 2], [3, 4], [5, 6]])
v = leg.legvander(x, 3)
assert_(v.shape == (3, 2, 4))
for i in range(4):
coef = [0]*i + [1]
assert_almost_equal(v[..., i], leg.legval(x, coef))
def test_legvander2d(self):
# also tests polyval2d for non-square coefficient array
x1, x2, x3 = self.x
c = np.random.random((2, 3))
van = leg.legvander2d(x1, x2, [1, 2])
tgt = leg.legval2d(x1, x2, c)
res = np.dot(van, c.flat)
assert_almost_equal(res, tgt)
# check shape
van = leg.legvander2d([x1], [x2], [1, 2])
assert_(van.shape == (1, 5, 6))
def test_legvander3d(self):
# also tests polyval3d for non-square coefficient array
x1, x2, x3 = self.x
c = np.random.random((2, 3, 4))
van = leg.legvander3d(x1, x2, x3, [1, 2, 3])
tgt = leg.legval3d(x1, x2, x3, c)
res = np.dot(van, c.flat)
assert_almost_equal(res, tgt)
# check shape
van = leg.legvander3d([x1], [x2], [x3], [1, 2, 3])
assert_(van.shape == (1, 5, 24))
class TestFitting(object):
def test_legfit(self):
def f(x):
return x*(x - 1)*(x - 2)
def f2(x):
return x**4 + x**2 + 1
# Test exceptions
assert_raises(ValueError, leg.legfit, [1], [1], -1)
assert_raises(TypeError, leg.legfit, [[1]], [1], 0)
assert_raises(TypeError, leg.legfit, [], [1], 0)
assert_raises(TypeError, leg.legfit, [1], [[[1]]], 0)
assert_raises(TypeError, leg.legfit, [1, 2], [1], 0)
assert_raises(TypeError, leg.legfit, [1], [1, 2], 0)
assert_raises(TypeError, leg.legfit, [1], [1], 0, w=[[1]])
assert_raises(TypeError, leg.legfit, [1], [1], 0, w=[1, 1])
assert_raises(ValueError, leg.legfit, [1], [1], [-1,])
assert_raises(ValueError, leg.legfit, [1], [1], [2, -1, 6])
assert_raises(TypeError, leg.legfit, [1], [1], [])
# Test fit
x = np.linspace(0, 2)
y = f(x)
#
coef3 = leg.legfit(x, y, 3)
assert_equal(len(coef3), 4)
assert_almost_equal(leg.legval(x, coef3), y)
coef3 = leg.legfit(x, y, [0, 1, 2, 3])
assert_equal(len(coef3), 4)
assert_almost_equal(leg.legval(x, coef3), y)
#
coef4 = leg.legfit(x, y, 4)
assert_equal(len(coef4), 5)
assert_almost_equal(leg.legval(x, coef4), y)
coef4 = leg.legfit(x, y, [0, 1, 2, 3, 4])
assert_equal(len(coef4), 5)
assert_almost_equal(leg.legval(x, coef4), y)
# check things still work if deg is not in strict increasing
coef4 = leg.legfit(x, y, [2, 3, 4, 1, 0])
assert_equal(len(coef4), 5)
assert_almost_equal(leg.legval(x, coef4), y)
#
coef2d = leg.legfit(x, np.array([y, y]).T, 3)
assert_almost_equal(coef2d, np.array([coef3, coef3]).T)
coef2d = leg.legfit(x, np.array([y, y]).T, [0, 1, 2, 3])
assert_almost_equal(coef2d, np.array([coef3, coef3]).T)
# test weighting
w = np.zeros_like(x)
yw = y.copy()
w[1::2] = 1
y[0::2] = 0
wcoef3 = leg.legfit(x, yw, 3, w=w)
assert_almost_equal(wcoef3, coef3)
wcoef3 = leg.legfit(x, yw, [0, 1, 2, 3], w=w)
assert_almost_equal(wcoef3, coef3)
#
wcoef2d = leg.legfit(x, np.array([yw, yw]).T, 3, w=w)
assert_almost_equal(wcoef2d, np.array([coef3, coef3]).T)
wcoef2d = leg.legfit(x, np.array([yw, yw]).T, [0, 1, 2, 3], w=w)
assert_almost_equal(wcoef2d, np.array([coef3, coef3]).T)
# test scaling with complex values x points whose square
# is zero when summed.
x = [1, 1j, -1, -1j]
assert_almost_equal(leg.legfit(x, x, 1), [0, 1])
assert_almost_equal(leg.legfit(x, x, [0, 1]), [0, 1])
# test fitting only even Legendre polynomials
x = np.linspace(-1, 1)
y = f2(x)
coef1 = leg.legfit(x, y, 4)
assert_almost_equal(leg.legval(x, coef1), y)
coef2 = leg.legfit(x, y, [0, 2, 4])
assert_almost_equal(leg.legval(x, coef2), y)
assert_almost_equal(coef1, coef2)
class TestCompanion(object):
def test_raises(self):
assert_raises(ValueError, leg.legcompanion, [])
assert_raises(ValueError, leg.legcompanion, [1])
def test_dimensions(self):
for i in range(1, 5):
coef = [0]*i + [1]
assert_(leg.legcompanion(coef).shape == (i, i))
def test_linear_root(self):
assert_(leg.legcompanion([1, 2])[0, 0] == -.5)
class TestGauss(object):
def test_100(self):
x, w = leg.leggauss(100)
# test orthogonality. Note that the results need to be normalized,
# otherwise the huge values that can arise from fast growing
# functions like Laguerre can be very confusing.
v = leg.legvander(x, 99)
vv = np.dot(v.T * w, v)
vd = 1/np.sqrt(vv.diagonal())
vv = vd[:, None] * vv * vd
assert_almost_equal(vv, np.eye(100))
# check that the integral of 1 is correct
tgt = 2.0
assert_almost_equal(w.sum(), tgt)
class TestMisc(object):
def test_legfromroots(self):
res = leg.legfromroots([])
assert_almost_equal(trim(res), [1])
for i in range(1, 5):
roots = np.cos(np.linspace(-np.pi, 0, 2*i + 1)[1::2])
pol = leg.legfromroots(roots)
res = leg.legval(roots, pol)
tgt = 0
assert_(len(pol) == i + 1)
assert_almost_equal(leg.leg2poly(pol)[-1], 1)
assert_almost_equal(res, tgt)
def test_legroots(self):
assert_almost_equal(leg.legroots([1]), [])
assert_almost_equal(leg.legroots([1, 2]), [-.5])
for i in range(2, 5):
tgt = np.linspace(-1, 1, i)
res = leg.legroots(leg.legfromroots(tgt))
assert_almost_equal(trim(res), trim(tgt))
def test_legtrim(self):
coef = [2, -1, 1, 0]
# Test exceptions
assert_raises(ValueError, leg.legtrim, coef, -1)
# Test results
assert_equal(leg.legtrim(coef), coef[:-1])
assert_equal(leg.legtrim(coef, 1), coef[:-3])
assert_equal(leg.legtrim(coef, 2), [0])
def test_legline(self):
assert_equal(leg.legline(3, 4), [3, 4])
def test_leg2poly(self):
for i in range(10):
assert_almost_equal(leg.leg2poly([0]*i + [1]), Llist[i])
def test_poly2leg(self):
for i in range(10):
assert_almost_equal(leg.poly2leg(Llist[i]), [0]*i + [1])
def test_weight(self):
x = np.linspace(-1, 1, 11)
tgt = 1.
res = leg.legweight(x)
assert_almost_equal(res, tgt)
if __name__ == "__main__":
run_module_suite()

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"""Tests for polynomial module.
"""
from __future__ import division, absolute_import, print_function
import numpy as np
import numpy.polynomial.polynomial as poly
from numpy.testing import (
assert_almost_equal, assert_raises, assert_equal, assert_,
run_module_suite
)
def trim(x):
return poly.polytrim(x, tol=1e-6)
T0 = [1]
T1 = [0, 1]
T2 = [-1, 0, 2]
T3 = [0, -3, 0, 4]
T4 = [1, 0, -8, 0, 8]
T5 = [0, 5, 0, -20, 0, 16]
T6 = [-1, 0, 18, 0, -48, 0, 32]
T7 = [0, -7, 0, 56, 0, -112, 0, 64]
T8 = [1, 0, -32, 0, 160, 0, -256, 0, 128]
T9 = [0, 9, 0, -120, 0, 432, 0, -576, 0, 256]
Tlist = [T0, T1, T2, T3, T4, T5, T6, T7, T8, T9]
class TestConstants(object):
def test_polydomain(self):
assert_equal(poly.polydomain, [-1, 1])
def test_polyzero(self):
assert_equal(poly.polyzero, [0])
def test_polyone(self):
assert_equal(poly.polyone, [1])
def test_polyx(self):
assert_equal(poly.polyx, [0, 1])
class TestArithmetic(object):
def test_polyadd(self):
for i in range(5):
for j in range(5):
msg = "At i=%d, j=%d" % (i, j)
tgt = np.zeros(max(i, j) + 1)
tgt[i] += 1
tgt[j] += 1
res = poly.polyadd([0]*i + [1], [0]*j + [1])
assert_equal(trim(res), trim(tgt), err_msg=msg)
def test_polysub(self):
for i in range(5):
for j in range(5):
msg = "At i=%d, j=%d" % (i, j)
tgt = np.zeros(max(i, j) + 1)
tgt[i] += 1
tgt[j] -= 1
res = poly.polysub([0]*i + [1], [0]*j + [1])
assert_equal(trim(res), trim(tgt), err_msg=msg)
def test_polymulx(self):
assert_equal(poly.polymulx([0]), [0])
assert_equal(poly.polymulx([1]), [0, 1])
for i in range(1, 5):
ser = [0]*i + [1]
tgt = [0]*(i + 1) + [1]
assert_equal(poly.polymulx(ser), tgt)
def test_polymul(self):
for i in range(5):
for j in range(5):
msg = "At i=%d, j=%d" % (i, j)
tgt = np.zeros(i + j + 1)
tgt[i + j] += 1
res = poly.polymul([0]*i + [1], [0]*j + [1])
assert_equal(trim(res), trim(tgt), err_msg=msg)
def test_polydiv(self):
# check zero division
assert_raises(ZeroDivisionError, poly.polydiv, [1], [0])
# check scalar division
quo, rem = poly.polydiv([2], [2])
assert_equal((quo, rem), (1, 0))
quo, rem = poly.polydiv([2, 2], [2])
assert_equal((quo, rem), ((1, 1), 0))
# check rest.
for i in range(5):
for j in range(5):
msg = "At i=%d, j=%d" % (i, j)
ci = [0]*i + [1, 2]
cj = [0]*j + [1, 2]
tgt = poly.polyadd(ci, cj)
quo, rem = poly.polydiv(tgt, ci)
res = poly.polyadd(poly.polymul(quo, ci), rem)
assert_equal(res, tgt, err_msg=msg)
class TestEvaluation(object):
# coefficients of 1 + 2*x + 3*x**2
c1d = np.array([1., 2., 3.])
c2d = np.einsum('i,j->ij', c1d, c1d)
c3d = np.einsum('i,j,k->ijk', c1d, c1d, c1d)
# some random values in [-1, 1)
x = np.random.random((3, 5))*2 - 1
y = poly.polyval(x, [1., 2., 3.])
def test_polyval(self):
#check empty input
assert_equal(poly.polyval([], [1]).size, 0)
#check normal input)
x = np.linspace(-1, 1)
y = [x**i for i in range(5)]
for i in range(5):
tgt = y[i]
res = poly.polyval(x, [0]*i + [1])
assert_almost_equal(res, tgt)
tgt = x*(x**2 - 1)
res = poly.polyval(x, [0, -1, 0, 1])
assert_almost_equal(res, tgt)
#check that shape is preserved
for i in range(3):
dims = [2]*i
x = np.zeros(dims)
assert_equal(poly.polyval(x, [1]).shape, dims)
assert_equal(poly.polyval(x, [1, 0]).shape, dims)
assert_equal(poly.polyval(x, [1, 0, 0]).shape, dims)
def test_polyvalfromroots(self):
# check exception for broadcasting x values over root array with
# too few dimensions
assert_raises(ValueError, poly.polyvalfromroots,
[1], [1], tensor=False)
# check empty input
assert_equal(poly.polyvalfromroots([], [1]).size, 0)
assert_(poly.polyvalfromroots([], [1]).shape == (0,))
# check empty input + multidimensional roots
assert_equal(poly.polyvalfromroots([], [[1] * 5]).size, 0)
assert_(poly.polyvalfromroots([], [[1] * 5]).shape == (5, 0))
# check scalar input
assert_equal(poly.polyvalfromroots(1, 1), 0)
assert_(poly.polyvalfromroots(1, np.ones((3, 3))).shape == (3,))
# check normal input)
x = np.linspace(-1, 1)
y = [x**i for i in range(5)]
for i in range(1, 5):
tgt = y[i]
res = poly.polyvalfromroots(x, [0]*i)
assert_almost_equal(res, tgt)
tgt = x*(x - 1)*(x + 1)
res = poly.polyvalfromroots(x, [-1, 0, 1])
assert_almost_equal(res, tgt)
# check that shape is preserved
for i in range(3):
dims = [2]*i
x = np.zeros(dims)
assert_equal(poly.polyvalfromroots(x, [1]).shape, dims)
assert_equal(poly.polyvalfromroots(x, [1, 0]).shape, dims)
assert_equal(poly.polyvalfromroots(x, [1, 0, 0]).shape, dims)
# check compatibility with factorization
ptest = [15, 2, -16, -2, 1]
r = poly.polyroots(ptest)
x = np.linspace(-1, 1)
assert_almost_equal(poly.polyval(x, ptest),
poly.polyvalfromroots(x, r))
# check multidimensional arrays of roots and values
# check tensor=False
rshape = (3, 5)
x = np.arange(-3, 2)
r = np.random.randint(-5, 5, size=rshape)
res = poly.polyvalfromroots(x, r, tensor=False)
tgt = np.empty(r.shape[1:])
for ii in range(tgt.size):
tgt[ii] = poly.polyvalfromroots(x[ii], r[:, ii])
assert_equal(res, tgt)
# check tensor=True
x = np.vstack([x, 2*x])
res = poly.polyvalfromroots(x, r, tensor=True)
tgt = np.empty(r.shape[1:] + x.shape)
for ii in range(r.shape[1]):
for jj in range(x.shape[0]):
tgt[ii, jj, :] = poly.polyvalfromroots(x[jj], r[:, ii])
assert_equal(res, tgt)
def test_polyval2d(self):
x1, x2, x3 = self.x
y1, y2, y3 = self.y
#test exceptions
assert_raises(ValueError, poly.polyval2d, x1, x2[:2], self.c2d)
#test values
tgt = y1*y2
res = poly.polyval2d(x1, x2, self.c2d)
assert_almost_equal(res, tgt)
#test shape
z = np.ones((2, 3))
res = poly.polyval2d(z, z, self.c2d)
assert_(res.shape == (2, 3))
def test_polyval3d(self):
x1, x2, x3 = self.x
y1, y2, y3 = self.y
#test exceptions
assert_raises(ValueError, poly.polyval3d, x1, x2, x3[:2], self.c3d)
#test values
tgt = y1*y2*y3
res = poly.polyval3d(x1, x2, x3, self.c3d)
assert_almost_equal(res, tgt)
#test shape
z = np.ones((2, 3))
res = poly.polyval3d(z, z, z, self.c3d)
assert_(res.shape == (2, 3))
def test_polygrid2d(self):
x1, x2, x3 = self.x
y1, y2, y3 = self.y
#test values
tgt = np.einsum('i,j->ij', y1, y2)
res = poly.polygrid2d(x1, x2, self.c2d)
assert_almost_equal(res, tgt)
#test shape
z = np.ones((2, 3))
res = poly.polygrid2d(z, z, self.c2d)
assert_(res.shape == (2, 3)*2)
def test_polygrid3d(self):
x1, x2, x3 = self.x
y1, y2, y3 = self.y
#test values
tgt = np.einsum('i,j,k->ijk', y1, y2, y3)
res = poly.polygrid3d(x1, x2, x3, self.c3d)
assert_almost_equal(res, tgt)
#test shape
z = np.ones((2, 3))
res = poly.polygrid3d(z, z, z, self.c3d)
assert_(res.shape == (2, 3)*3)
class TestIntegral(object):
def test_polyint(self):
# check exceptions
assert_raises(ValueError, poly.polyint, [0], .5)
assert_raises(ValueError, poly.polyint, [0], -1)
assert_raises(ValueError, poly.polyint, [0], 1, [0, 0])
assert_raises(ValueError, poly.polyint, [0], lbnd=[0])
assert_raises(ValueError, poly.polyint, [0], scl=[0])
assert_raises(ValueError, poly.polyint, [0], axis=.5)
# test integration of zero polynomial
for i in range(2, 5):
k = [0]*(i - 2) + [1]
res = poly.polyint([0], m=i, k=k)
assert_almost_equal(res, [0, 1])
# check single integration with integration constant
for i in range(5):
scl = i + 1
pol = [0]*i + [1]
tgt = [i] + [0]*i + [1/scl]
res = poly.polyint(pol, m=1, k=[i])
assert_almost_equal(trim(res), trim(tgt))
# check single integration with integration constant and lbnd
for i in range(5):
scl = i + 1
pol = [0]*i + [1]
res = poly.polyint(pol, m=1, k=[i], lbnd=-1)
assert_almost_equal(poly.polyval(-1, res), i)
# check single integration with integration constant and scaling
for i in range(5):
scl = i + 1
pol = [0]*i + [1]
tgt = [i] + [0]*i + [2/scl]
res = poly.polyint(pol, m=1, k=[i], scl=2)
assert_almost_equal(trim(res), trim(tgt))
# check multiple integrations with default k
for i in range(5):
for j in range(2, 5):
pol = [0]*i + [1]
tgt = pol[:]
for k in range(j):
tgt = poly.polyint(tgt, m=1)
res = poly.polyint(pol, m=j)
assert_almost_equal(trim(res), trim(tgt))
# check multiple integrations with defined k
for i in range(5):
for j in range(2, 5):
pol = [0]*i + [1]
tgt = pol[:]
for k in range(j):
tgt = poly.polyint(tgt, m=1, k=[k])
res = poly.polyint(pol, m=j, k=list(range(j)))
assert_almost_equal(trim(res), trim(tgt))
# check multiple integrations with lbnd
for i in range(5):
for j in range(2, 5):
pol = [0]*i + [1]
tgt = pol[:]
for k in range(j):
tgt = poly.polyint(tgt, m=1, k=[k], lbnd=-1)
res = poly.polyint(pol, m=j, k=list(range(j)), lbnd=-1)
assert_almost_equal(trim(res), trim(tgt))
# check multiple integrations with scaling
for i in range(5):
for j in range(2, 5):
pol = [0]*i + [1]
tgt = pol[:]
for k in range(j):
tgt = poly.polyint(tgt, m=1, k=[k], scl=2)
res = poly.polyint(pol, m=j, k=list(range(j)), scl=2)
assert_almost_equal(trim(res), trim(tgt))
def test_polyint_axis(self):
# check that axis keyword works
c2d = np.random.random((3, 4))
tgt = np.vstack([poly.polyint(c) for c in c2d.T]).T
res = poly.polyint(c2d, axis=0)
assert_almost_equal(res, tgt)
tgt = np.vstack([poly.polyint(c) for c in c2d])
res = poly.polyint(c2d, axis=1)
assert_almost_equal(res, tgt)
tgt = np.vstack([poly.polyint(c, k=3) for c in c2d])
res = poly.polyint(c2d, k=3, axis=1)
assert_almost_equal(res, tgt)
class TestDerivative(object):
def test_polyder(self):
# check exceptions
assert_raises(ValueError, poly.polyder, [0], .5)
assert_raises(ValueError, poly.polyder, [0], -1)
# check that zeroth derivative does nothing
for i in range(5):
tgt = [0]*i + [1]
res = poly.polyder(tgt, m=0)
assert_equal(trim(res), trim(tgt))
# check that derivation is the inverse of integration
for i in range(5):
for j in range(2, 5):
tgt = [0]*i + [1]
res = poly.polyder(poly.polyint(tgt, m=j), m=j)
assert_almost_equal(trim(res), trim(tgt))
# check derivation with scaling
for i in range(5):
for j in range(2, 5):
tgt = [0]*i + [1]
res = poly.polyder(poly.polyint(tgt, m=j, scl=2), m=j, scl=.5)
assert_almost_equal(trim(res), trim(tgt))
def test_polyder_axis(self):
# check that axis keyword works
c2d = np.random.random((3, 4))
tgt = np.vstack([poly.polyder(c) for c in c2d.T]).T
res = poly.polyder(c2d, axis=0)
assert_almost_equal(res, tgt)
tgt = np.vstack([poly.polyder(c) for c in c2d])
res = poly.polyder(c2d, axis=1)
assert_almost_equal(res, tgt)
class TestVander(object):
# some random values in [-1, 1)
x = np.random.random((3, 5))*2 - 1
def test_polyvander(self):
# check for 1d x
x = np.arange(3)
v = poly.polyvander(x, 3)
assert_(v.shape == (3, 4))
for i in range(4):
coef = [0]*i + [1]
assert_almost_equal(v[..., i], poly.polyval(x, coef))
# check for 2d x
x = np.array([[1, 2], [3, 4], [5, 6]])
v = poly.polyvander(x, 3)
assert_(v.shape == (3, 2, 4))
for i in range(4):
coef = [0]*i + [1]
assert_almost_equal(v[..., i], poly.polyval(x, coef))
def test_polyvander2d(self):
# also tests polyval2d for non-square coefficient array
x1, x2, x3 = self.x
c = np.random.random((2, 3))
van = poly.polyvander2d(x1, x2, [1, 2])
tgt = poly.polyval2d(x1, x2, c)
res = np.dot(van, c.flat)
assert_almost_equal(res, tgt)
# check shape
van = poly.polyvander2d([x1], [x2], [1, 2])
assert_(van.shape == (1, 5, 6))
def test_polyvander3d(self):
# also tests polyval3d for non-square coefficient array
x1, x2, x3 = self.x
c = np.random.random((2, 3, 4))
van = poly.polyvander3d(x1, x2, x3, [1, 2, 3])
tgt = poly.polyval3d(x1, x2, x3, c)
res = np.dot(van, c.flat)
assert_almost_equal(res, tgt)
# check shape
van = poly.polyvander3d([x1], [x2], [x3], [1, 2, 3])
assert_(van.shape == (1, 5, 24))
class TestCompanion(object):
def test_raises(self):
assert_raises(ValueError, poly.polycompanion, [])
assert_raises(ValueError, poly.polycompanion, [1])
def test_dimensions(self):
for i in range(1, 5):
coef = [0]*i + [1]
assert_(poly.polycompanion(coef).shape == (i, i))
def test_linear_root(self):
assert_(poly.polycompanion([1, 2])[0, 0] == -.5)
class TestMisc(object):
def test_polyfromroots(self):
res = poly.polyfromroots([])
assert_almost_equal(trim(res), [1])
for i in range(1, 5):
roots = np.cos(np.linspace(-np.pi, 0, 2*i + 1)[1::2])
tgt = Tlist[i]
res = poly.polyfromroots(roots)*2**(i-1)
assert_almost_equal(trim(res), trim(tgt))
def test_polyroots(self):
assert_almost_equal(poly.polyroots([1]), [])
assert_almost_equal(poly.polyroots([1, 2]), [-.5])
for i in range(2, 5):
tgt = np.linspace(-1, 1, i)
res = poly.polyroots(poly.polyfromroots(tgt))
assert_almost_equal(trim(res), trim(tgt))
def test_polyfit(self):
def f(x):
return x*(x - 1)*(x - 2)
def f2(x):
return x**4 + x**2 + 1
# Test exceptions
assert_raises(ValueError, poly.polyfit, [1], [1], -1)
assert_raises(TypeError, poly.polyfit, [[1]], [1], 0)
assert_raises(TypeError, poly.polyfit, [], [1], 0)
assert_raises(TypeError, poly.polyfit, [1], [[[1]]], 0)
assert_raises(TypeError, poly.polyfit, [1, 2], [1], 0)
assert_raises(TypeError, poly.polyfit, [1], [1, 2], 0)
assert_raises(TypeError, poly.polyfit, [1], [1], 0, w=[[1]])
assert_raises(TypeError, poly.polyfit, [1], [1], 0, w=[1, 1])
assert_raises(ValueError, poly.polyfit, [1], [1], [-1,])
assert_raises(ValueError, poly.polyfit, [1], [1], [2, -1, 6])
assert_raises(TypeError, poly.polyfit, [1], [1], [])
# Test fit
x = np.linspace(0, 2)
y = f(x)
#
coef3 = poly.polyfit(x, y, 3)
assert_equal(len(coef3), 4)
assert_almost_equal(poly.polyval(x, coef3), y)
coef3 = poly.polyfit(x, y, [0, 1, 2, 3])
assert_equal(len(coef3), 4)
assert_almost_equal(poly.polyval(x, coef3), y)
#
coef4 = poly.polyfit(x, y, 4)
assert_equal(len(coef4), 5)
assert_almost_equal(poly.polyval(x, coef4), y)
coef4 = poly.polyfit(x, y, [0, 1, 2, 3, 4])
assert_equal(len(coef4), 5)
assert_almost_equal(poly.polyval(x, coef4), y)
#
coef2d = poly.polyfit(x, np.array([y, y]).T, 3)
assert_almost_equal(coef2d, np.array([coef3, coef3]).T)
coef2d = poly.polyfit(x, np.array([y, y]).T, [0, 1, 2, 3])
assert_almost_equal(coef2d, np.array([coef3, coef3]).T)
# test weighting
w = np.zeros_like(x)
yw = y.copy()
w[1::2] = 1
yw[0::2] = 0
wcoef3 = poly.polyfit(x, yw, 3, w=w)
assert_almost_equal(wcoef3, coef3)
wcoef3 = poly.polyfit(x, yw, [0, 1, 2, 3], w=w)
assert_almost_equal(wcoef3, coef3)
#
wcoef2d = poly.polyfit(x, np.array([yw, yw]).T, 3, w=w)
assert_almost_equal(wcoef2d, np.array([coef3, coef3]).T)
wcoef2d = poly.polyfit(x, np.array([yw, yw]).T, [0, 1, 2, 3], w=w)
assert_almost_equal(wcoef2d, np.array([coef3, coef3]).T)
# test scaling with complex values x points whose square
# is zero when summed.
x = [1, 1j, -1, -1j]
assert_almost_equal(poly.polyfit(x, x, 1), [0, 1])
assert_almost_equal(poly.polyfit(x, x, [0, 1]), [0, 1])
# test fitting only even Polyendre polynomials
x = np.linspace(-1, 1)
y = f2(x)
coef1 = poly.polyfit(x, y, 4)
assert_almost_equal(poly.polyval(x, coef1), y)
coef2 = poly.polyfit(x, y, [0, 2, 4])
assert_almost_equal(poly.polyval(x, coef2), y)
assert_almost_equal(coef1, coef2)
def test_polytrim(self):
coef = [2, -1, 1, 0]
# Test exceptions
assert_raises(ValueError, poly.polytrim, coef, -1)
# Test results
assert_equal(poly.polytrim(coef), coef[:-1])
assert_equal(poly.polytrim(coef, 1), coef[:-3])
assert_equal(poly.polytrim(coef, 2), [0])
def test_polyline(self):
assert_equal(poly.polyline(3, 4), [3, 4])
if __name__ == "__main__":
run_module_suite()

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"""Tests for polyutils module.
"""
from __future__ import division, absolute_import, print_function
import numpy as np
import numpy.polynomial.polyutils as pu
from numpy.testing import (
assert_almost_equal, assert_raises, assert_equal, assert_,
run_module_suite
)
class TestMisc(object):
def test_trimseq(self):
for i in range(5):
tgt = [1]
res = pu.trimseq([1] + [0]*5)
assert_equal(res, tgt)
def test_as_series(self):
# check exceptions
assert_raises(ValueError, pu.as_series, [[]])
assert_raises(ValueError, pu.as_series, [[[1, 2]]])
assert_raises(ValueError, pu.as_series, [[1], ['a']])
# check common types
types = ['i', 'd', 'O']
for i in range(len(types)):
for j in range(i):
ci = np.ones(1, types[i])
cj = np.ones(1, types[j])
[resi, resj] = pu.as_series([ci, cj])
assert_(resi.dtype.char == resj.dtype.char)
assert_(resj.dtype.char == types[i])
def test_trimcoef(self):
coef = [2, -1, 1, 0]
# Test exceptions
assert_raises(ValueError, pu.trimcoef, coef, -1)
# Test results
assert_equal(pu.trimcoef(coef), coef[:-1])
assert_equal(pu.trimcoef(coef, 1), coef[:-3])
assert_equal(pu.trimcoef(coef, 2), [0])
class TestDomain(object):
def test_getdomain(self):
# test for real values
x = [1, 10, 3, -1]
tgt = [-1, 10]
res = pu.getdomain(x)
assert_almost_equal(res, tgt)
# test for complex values
x = [1 + 1j, 1 - 1j, 0, 2]
tgt = [-1j, 2 + 1j]
res = pu.getdomain(x)
assert_almost_equal(res, tgt)
def test_mapdomain(self):
# test for real values
dom1 = [0, 4]
dom2 = [1, 3]
tgt = dom2
res = pu. mapdomain(dom1, dom1, dom2)
assert_almost_equal(res, tgt)
# test for complex values
dom1 = [0 - 1j, 2 + 1j]
dom2 = [-2, 2]
tgt = dom2
x = dom1
res = pu.mapdomain(x, dom1, dom2)
assert_almost_equal(res, tgt)
# test for multidimensional arrays
dom1 = [0, 4]
dom2 = [1, 3]
tgt = np.array([dom2, dom2])
x = np.array([dom1, dom1])
res = pu.mapdomain(x, dom1, dom2)
assert_almost_equal(res, tgt)
# test that subtypes are preserved.
dom1 = [0, 4]
dom2 = [1, 3]
x = np.matrix([dom1, dom1])
res = pu.mapdomain(x, dom1, dom2)
assert_(isinstance(res, np.matrix))
def test_mapparms(self):
# test for real values
dom1 = [0, 4]
dom2 = [1, 3]
tgt = [1, .5]
res = pu. mapparms(dom1, dom2)
assert_almost_equal(res, tgt)
# test for complex values
dom1 = [0 - 1j, 2 + 1j]
dom2 = [-2, 2]
tgt = [-1 + 1j, 1 - 1j]
res = pu.mapparms(dom1, dom2)
assert_almost_equal(res, tgt)
if __name__ == "__main__":
run_module_suite()

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from __future__ import division, absolute_import, print_function
import numpy.polynomial as poly
from numpy.testing import run_module_suite, assert_equal
class TestStr(object):
def test_polynomial_str(self):
res = str(poly.Polynomial([0, 1]))
tgt = 'poly([0. 1.])'
assert_equal(res, tgt)
def test_chebyshev_str(self):
res = str(poly.Chebyshev([0, 1]))
tgt = 'cheb([0. 1.])'
assert_equal(res, tgt)
def test_legendre_str(self):
res = str(poly.Legendre([0, 1]))
tgt = 'leg([0. 1.])'
assert_equal(res, tgt)
def test_hermite_str(self):
res = str(poly.Hermite([0, 1]))
tgt = 'herm([0. 1.])'
assert_equal(res, tgt)
def test_hermiteE_str(self):
res = str(poly.HermiteE([0, 1]))
tgt = 'herme([0. 1.])'
assert_equal(res, tgt)
def test_laguerre_str(self):
res = str(poly.Laguerre([0, 1]))
tgt = 'lag([0. 1.])'
assert_equal(res, tgt)
class TestRepr(object):
def test_polynomial_str(self):
res = repr(poly.Polynomial([0, 1]))
tgt = 'Polynomial([0., 1.], domain=[-1, 1], window=[-1, 1])'
assert_equal(res, tgt)
def test_chebyshev_str(self):
res = repr(poly.Chebyshev([0, 1]))
tgt = 'Chebyshev([0., 1.], domain=[-1, 1], window=[-1, 1])'
assert_equal(res, tgt)
def test_legendre_repr(self):
res = repr(poly.Legendre([0, 1]))
tgt = 'Legendre([0., 1.], domain=[-1, 1], window=[-1, 1])'
assert_equal(res, tgt)
def test_hermite_repr(self):
res = repr(poly.Hermite([0, 1]))
tgt = 'Hermite([0., 1.], domain=[-1, 1], window=[-1, 1])'
assert_equal(res, tgt)
def test_hermiteE_repr(self):
res = repr(poly.HermiteE([0, 1]))
tgt = 'HermiteE([0., 1.], domain=[-1, 1], window=[-1, 1])'
assert_equal(res, tgt)
def test_laguerre_repr(self):
res = repr(poly.Laguerre([0, 1]))
tgt = 'Laguerre([0., 1.], domain=[0, 1], window=[0, 1])'
assert_equal(res, tgt)
#
if __name__ == "__main__":
run_module_suite()