Spaces:
Running
Running
| """Test inter-conversion of different polynomial classes. | |
| This tests the convert and cast methods of all the polynomial classes. | |
| """ | |
| import operator as op | |
| from numbers import Number | |
| import pytest | |
| 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_, | |
| ) | |
| from numpy.polynomial.polyutils import RankWarning | |
| # | |
| # fixtures | |
| # | |
| classes = ( | |
| Polynomial, Legendre, Chebyshev, Laguerre, | |
| Hermite, HermiteE | |
| ) | |
| classids = tuple(cls.__name__ for cls in classes) | |
| def Poly(request): | |
| return request.param | |
| # | |
| # 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 = f"Result: {p1}\nTarget: {p2}" | |
| raise AssertionError(msg) | |
| # | |
| # Test conversion methods that depend on combinations of two classes. | |
| # | |
| Poly1 = Poly | |
| Poly2 = Poly | |
| def test_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 test_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)) | |
| # | |
| # test methods that depend on one class | |
| # | |
| def test_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 test_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 test_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 test_bad_conditioned_fit(Poly): | |
| x = [0., 0., 1.] | |
| y = [1., 2., 3.] | |
| # check RankWarning is raised | |
| with pytest.warns(RankWarning) as record: | |
| Poly.fit(x, y, 2) | |
| assert record[0].message.args[0] == "The fit may be poorly conditioned" | |
| def test_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 test_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 test_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 test_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 test_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 test_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 test_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 test_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, 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 test_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 test_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 test_roots(Poly): | |
| d = Poly.domain * 1.25 + .25 | |
| w = Poly.window | |
| tgt = np.linspace(d[0], d[1], 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 test_degree(Poly): | |
| p = Poly.basis(5) | |
| assert_equal(p.degree(), 5) | |
| def test_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 test_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 test_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 test_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 test_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 test_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 test_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 test_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 test_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 test_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 test_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) | |
| # | |
| # Test class method that only exists for some classes | |
| # | |
| class TestInterpolate: | |
| 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) | |