diff options
| -rw-r--r-- | numpy/core/tests/test_scalar_methods.py | 122 |
1 files changed, 76 insertions, 46 deletions
diff --git a/numpy/core/tests/test_scalar_methods.py b/numpy/core/tests/test_scalar_methods.py index 439fe9de2..0e4ac5f39 100644 --- a/numpy/core/tests/test_scalar_methods.py +++ b/numpy/core/tests/test_scalar_methods.py @@ -3,7 +3,11 @@ Test the scalar constructors, which also do type-coercion """ from __future__ import division, absolute_import, print_function +import os import fractions +import platform + +import pytest import numpy as np from numpy.testing import ( @@ -12,39 +16,23 @@ from numpy.testing import ( dec ) -float_types = [np.half, np.single, np.double, np.longdouble] - -def test_float_as_integer_ratio(): - # derived from the cpython test "test_floatasratio" - for ftype in float_types: - for f, ratio in [ - (0.875, (7, 8)), - (-0.875, (-7, 8)), - (0.0, (0, 1)), - (11.5, (23, 2)), - ]: - assert_equal(ftype(f).as_integer_ratio(), ratio) - - rstate = np.random.RandomState(0) - fi = np.finfo(ftype) - for i in range(1000): - exp = rstate.randint(fi.minexp, fi.maxexp - 1) - frac = rstate.rand() - f = np.ldexp(frac, exp, dtype=ftype) - - n, d = f.as_integer_ratio() - - try: - dn = np.longdouble(str(n)) - df = np.longdouble(str(d)) - except (OverflowError, RuntimeWarning): - # the values may not fit in any float type - continue +class TestAsIntegerRatio(object): + # derived in part from the cpython test "test_floatasratio" - assert_equal( - dn / df, f, - "{}/{} (dtype={})".format(n, d, ftype.__name__)) + @pytest.mark.parametrize("ftype", [ + np.half, np.single, np.double, np.longdouble]) + @pytest.mark.parametrize("f, ratio", [ + (0.875, (7, 8)), + (-0.875, (-7, 8)), + (0.0, (0, 1)), + (11.5, (23, 2)), + ]) + def test_small(self, ftype, f, ratio): + assert_equal(ftype(f).as_integer_ratio(), ratio) + @pytest.mark.parametrize("ftype", [ + np.half, np.single, np.double, np.longdouble]) + def test_simple_fractions(self, ftype): R = fractions.Fraction assert_equal(R(0, 1), R(*ftype(0.0).as_integer_ratio())) @@ -55,25 +43,67 @@ def test_float_as_integer_ratio(): assert_equal(R(-2100, 1), R(*ftype(-2100.0).as_integer_ratio())) + @pytest.mark.parametrize("ftype", [ + np.half, np.single, np.double, np.longdouble]) + def test_errors(self, ftype): assert_raises(OverflowError, ftype('inf').as_integer_ratio) assert_raises(OverflowError, ftype('-inf').as_integer_ratio) assert_raises(ValueError, ftype('nan').as_integer_ratio) + def test_against_known_values(self): + R = fractions.Fraction + assert_equal(R(1075, 512), + R(*np.half(2.1).as_integer_ratio())) + assert_equal(R(-1075, 512), + R(*np.half(-2.1).as_integer_ratio())) + assert_equal(R(4404019, 2097152), + R(*np.single(2.1).as_integer_ratio())) + assert_equal(R(-4404019, 2097152), + R(*np.single(-2.1).as_integer_ratio())) + assert_equal(R(4728779608739021, 2251799813685248), + R(*np.double(2.1).as_integer_ratio())) + assert_equal(R(-4728779608739021, 2251799813685248), + R(*np.double(-2.1).as_integer_ratio())) + # longdouble is platform depedent - assert_equal(R(1075, 512), - R(*np.half(2.1).as_integer_ratio())) - assert_equal(R(-1075, 512), - R(*np.half(-2.1).as_integer_ratio())) - assert_equal(R(4404019, 2097152), - R(*np.single(2.1).as_integer_ratio())) - assert_equal(R(-4404019, 2097152), - R(*np.single(-2.1).as_integer_ratio())) - assert_equal(R(4728779608739021, 2251799813685248), - R(*np.double(2.1).as_integer_ratio())) - assert_equal(R(-4728779608739021, 2251799813685248), - R(*np.double(-2.1).as_integer_ratio())) - # longdouble is platform depedent + @pytest.mark.parametrize("ftype, frac_vals, exp_vals", [ + # dtype test cases generated using hypothesis + # first five generated cases per dtype + (np.half, [0.0, 0.01154830649280303, 0.31082276347447274, + 0.527350517124794, 0.8308562335072596], + [0, 1, 0, -8, 12]), + (np.single, [0.0, 0.09248576989263226, 0.8160498218131407, + 0.17389442853722373, 0.7956044195067877], + [0, 12, 10, 17, -26]), + (np.double, [0.0, 0.031066908499895136, 0.5214135908877832, + 0.45780736035689296, 0.5906586745934036], + [0, -801, 51, 194, -653]), + pytest.param( + np.longdouble, + [0.0, 0.20492557202724854, 0.4277180662199366, 0.9888085019891495, + 0.9620175814461964], + [0, -7400, 14266, -7822, -8721], + marks=[ + pytest.mark.skipif( + np.finfo(np.double) == np.finfo(np.longdouble), + reason="long double is same as double"), + pytest.mark.skipif( + platform.machine().startswith("ppc"), + reason="IBM double double"), + ] + ) + ]) + def test_roundtrip(self, ftype, frac_vals, exp_vals): + for frac, exp in zip(frac_vals, exp_vals): + f = np.ldexp(frac, exp, dtype=ftype) + n, d = f.as_integer_ratio() + try: + # workaround for gh-9968 + nf = np.longdouble(str(n)) + df = np.longdouble(str(d)) + except (OverflowError, RuntimeWarning): + # the values may not fit in any float type + pytest.skip("longdouble too small on this platform") -if __name__ == "__main__": - run_module_suite() + assert_equal(nf / df, f, "{}/{}".format(n, d)) |