76 lines
1.8 KiB
Python
76 lines
1.8 KiB
Python
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import pytest
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import numpy as np
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from numpy.testing import assert_allclose
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import scipy.special as sc
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class TestExp1:
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def test_branch_cut(self):
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assert np.isnan(sc.exp1(-1))
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assert sc.exp1(complex(-1, 0)).imag == (
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-sc.exp1(complex(-1, -0.0)).imag
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)
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assert_allclose(
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sc.exp1(complex(-1, 0)),
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sc.exp1(-1 + 1e-20j),
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atol=0,
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rtol=1e-15
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)
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assert_allclose(
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sc.exp1(complex(-1, -0.0)),
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sc.exp1(-1 - 1e-20j),
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atol=0,
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rtol=1e-15
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)
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def test_834(self):
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# Regression test for #834
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a = sc.exp1(-complex(19.9999990))
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b = sc.exp1(-complex(19.9999991))
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assert_allclose(a.imag, b.imag, atol=0, rtol=1e-15)
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class TestExpi:
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@pytest.mark.parametrize('result', [
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sc.expi(complex(-1, 0)),
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sc.expi(complex(-1, -0.0)),
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sc.expi(-1)
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])
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def test_branch_cut(self, result):
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desired = -0.21938393439552027368 # Computed using Mpmath
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assert_allclose(result, desired, atol=0, rtol=1e-14)
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def test_near_branch_cut(self):
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lim_from_above = sc.expi(-1 + 1e-20j)
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lim_from_below = sc.expi(-1 - 1e-20j)
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assert_allclose(
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lim_from_above.real,
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lim_from_below.real,
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atol=0,
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rtol=1e-15
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)
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assert_allclose(
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lim_from_above.imag,
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-lim_from_below.imag,
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atol=0,
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rtol=1e-15
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)
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def test_continuity_on_positive_real_axis(self):
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assert_allclose(
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sc.expi(complex(1, 0)),
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sc.expi(complex(1, -0.0)),
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atol=0,
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rtol=1e-15
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)
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class TestExpn:
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def test_out_of_domain(self):
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assert all(np.isnan([sc.expn(-1, 1.0), sc.expn(1, -1.0)]))
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