projektAI/venv/Lib/site-packages/scipy/special/tests/test_exponential_integrals.py

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2021-06-06 22:13:05 +02:00
import pytest
import numpy as np
from numpy.testing import assert_allclose
import scipy.special as sc
class TestExp1(object):
def test_branch_cut(self):
assert np.isnan(sc.exp1(-1))
assert sc.exp1(complex(-1, 0)).imag == (
-sc.exp1(complex(-1, -0.0)).imag
)
assert_allclose(
sc.exp1(complex(-1, 0)),
sc.exp1(-1 + 1e-20j),
atol=0,
rtol=1e-15
)
assert_allclose(
sc.exp1(complex(-1, -0.0)),
sc.exp1(-1 - 1e-20j),
atol=0,
rtol=1e-15
)
def test_834(self):
# Regression test for #834
a = sc.exp1(-complex(19.9999990))
b = sc.exp1(-complex(19.9999991))
assert_allclose(a.imag, b.imag, atol=0, rtol=1e-15)
class TestExpi(object):
@pytest.mark.parametrize('result', [
sc.expi(complex(-1, 0)),
sc.expi(complex(-1, -0.0)),
sc.expi(-1)
])
def test_branch_cut(self, result):
desired = -0.21938393439552027368 # Computed using Mpmath
assert_allclose(result, desired, atol=0, rtol=1e-14)
def test_near_branch_cut(self):
lim_from_above = sc.expi(-1 + 1e-20j)
lim_from_below = sc.expi(-1 - 1e-20j)
assert_allclose(
lim_from_above.real,
lim_from_below.real,
atol=0,
rtol=1e-15
)
assert_allclose(
lim_from_above.imag,
-lim_from_below.imag,
atol=0,
rtol=1e-15
)
def test_continuity_on_positive_real_axis(self):
assert_allclose(
sc.expi(complex(1, 0)),
sc.expi(complex(1, -0.0)),
atol=0,
rtol=1e-15
)
class TestExpn(object):
def test_out_of_domain(self):
assert all(np.isnan([sc.expn(-1, 1.0), sc.expn(1, -1.0)]))