8000 add math.fmax and math.fmin · python/cpython@a82d298 · GitHub
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add math.fmax and math.fmin
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‎Doc/library/math.rst

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@@ -42,6 +42,8 @@ noted otherwise, all return values are floats.
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:func:`fabs(x) <fabs>` Absolute value of *x*
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:func:`floor(x) <floor>` Floor of *x*, the largest integer less than or equal to *x*
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:func:`fma(x, y, z) <fma>` Fused multiply-add operation: ``(x * y) + z``
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:func:`fmax(x, y) <fmax>` Maximum of two floating-point values
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:func:`fmin(x, y) <fmin>` Minimum of two floating-point values
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:func:`fmod(x, y) <fmod>` Remainder of division ``x / y``
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:func:`modf(x) <modf>` Fractional and integer parts of *x*
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:func:`remainder(x, y) <remainder>` Remainder of *x* with respect to *y*
@@ -247,6 +249,26 @@ Floating point arithmetic
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.. versionadded:: 3.13
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.. function:: fmax(x, y, /)
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Get the larger of two floating-point values, treating NaNs as missing data.
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If *x* and *y* are NaNs of same sign *s*, return ``copysign(nan, s)``.
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If *x* and *y* are NaNs of different sign, return ``copysign(nan, 1)``.
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.. versionadded:: next
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.. function:: fmin(x, y, /)
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Get the smaller of two floating-point values, treating NaNs as missing data.
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If *x* and *y* are NaNs of same sign *s*, return ``copysign(nan, s)``.
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If *x* and *y* are NaNs of different sign, return ``copysign(nan, -1)``.
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.. versionadded:: next
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.. function:: fmod(x, y)
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Return the floating-point remainder of ``x / y``,

‎Doc/whatsnew/3.15.rst

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@@ -115,6 +115,9 @@ math
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* Add :func:`math.isnormal` and :func:`math.issubnormal` functions.
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(Contributed by Sergey B Kirpichev in :gh:`132908`.)
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* Add :func:`math.fmax` and :func:`math.fmin` functions.
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(Contributed by Bénédikt Tran in :gh:`135853`.)
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os.path
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-------

‎Lib/test/test_math.py

Lines changed: 105 additions & 3 deletions
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@@ -17,6 +17,7 @@
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eps = 1E-05
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NAN = float('nan')
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NNAN = float('-nan')
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INF = float('inf')
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NINF = float('-inf')
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FLOAT_MAX = sys.float_info.max
@@ -37,6 +38,11 @@
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test_file = os.path.join(test_dir, 'mathdata', 'cmath_testcases.txt')
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def is_signed_nan(x, x0):
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"""Check if x is a NaN with the same sign as x0."""
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return math.isnan(x) and math.copysign(1, x) == math.copysign(1, x0)
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def to_ulps(x):
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"""Convert a non-NaN float x to an integer, in such a way that
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adjacent floats are converted to adjacent integers. Then
@@ -253,9 +259,10 @@ def ftest(self, name, got, expected, ulp_tol=5, abs_tol=0.0):
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non-finite floats, exact equality is demanded. Also, nan==nan
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in this function.
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"""
256-
failure = result_check(expected, got, ulp_tol, abs_tol)
257-
if failure is not None:
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self.fail("{}: {}".format(name, failure))
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with self.subTest(name):
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failure = result_check(expected, got, ulp_tol, abs_tol)
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if failure is not None:
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self.fail(failure)
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def testConstants(self):
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# Ref: Abramowitz & Stegun (Dover, 1965)
@@ -623,6 +630,101 @@ def testFmod(self):
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self.assertEqual(math.fmod(0.0, NINF), 0.0)
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self.assertRaises(ValueError, math.fmod, INF, INF)
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def test_fmax(self):
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self.assertRaises(TypeError, math.fmax)
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self.assertRaises(TypeError, math.fmax, 'x', 'y')
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self.assertEqual(math.fmax(0., 0.), 0.)
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self.assertEqual(math.fmax(0., -0.), 0.)
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self.assertEqual(math.fmax(-0., 0.), 0.)
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self.assertEqual(math.fmax(1., 0.), 1.)
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self.assertEqual(math.fmax(0., 1.), 1.)
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self.assertEqual(math.fmax(1., -0.), 1.)
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self.assertEqual(math.fmax(-0., 1.), 1.)
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self.assertEqual(math.fmax(-1., 0.), 0.)
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self.assertEqual(math.fmax(0., -1.), 0.)
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self.assertEqual(math.fmax(-1., -0.), -0.)
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self.assertEqual(math.fmax(-0., -1.), -0.)
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for x in [NINF, -1., -0., 0., 1., INF]:
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self.assertFalse(math.isnan(x))
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with self.subTest("math.fmax(INF, x)", x=x):
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self.assertEqual(math.fmax(INF, x), INF)
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with self.subTest("math.fmax(x, INF)", x=x):
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self.assertEqual(math.fmax(x, INF), INF)
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with self.subTest("math.fmax(NINF, x)", x=x):
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self.assertEqual(math.fmax(NINF, x), x)
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with self.subTest("math.fmax(x, NINF)", x=x):
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self.assertEqual(math.fmax(x, NINF), x)
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@requires_IEEE_754
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def test_fmax_nans(self):
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# When exactly one operand is NaN, the other is returned.
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for x in [NINF, -1., -0., 0., 1., INF]:
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with self.subTest(x=x):
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self.assertFalse(math.isnan(math.fmax(NAN, x)))
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self.assertFalse(math.isnan(math.fmax(x, NAN)))
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self.assertFalse(math.isnan(math.fmax(NNAN, x)))
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self.assertFalse(math.isnan(math.fmax(x, NNAN)))
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# When operands are NaNs with identical sign, return this signed NaN.
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self.assertTrue(is_signed_nan(math.fmax(NAN, NAN), 1))
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self.assertTrue(is_signed_nan(math.fmax(NNAN, NNAN), -1))
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# When operands are NaNs of different signs, return the positive NaN.
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self.assertTrue(is_signed_nan(math.fmax(NAN, NNAN), 1))
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self.assertTrue(is_signed_nan(math.fmax(NNAN, NAN), 1))
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def test_fmin(self):
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self.assertRaises(TypeError, math.fmin)
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self.assertRaises(TypeError, math.fmin, 'x', 'y')
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self.assertEqual(math.fmin(0., 0.), 0.)
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self.assertEqual(math.fmin(0., -0.), -0.)
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self.assertEqual(math.fmin(-0., 0.), -0.)
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self.assertEqual(math.fmin(1., 0.), 0.)
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self.assertEqual(math.fmin(0., 1.), 0.)
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self.assertEqual(math.fmin(1., -0.), -0.)
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self.assertEqual(math.fmin(-0., 1.), -0.)
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self.assertEqual(math.fmin(-1., 0.), -1.)
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self.assertEqual(math.fmin(0., -1.), -1.)
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self.assertEqual(math.fmin(-1., -0.), -1.)
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self.assertEqual(math.fmin(-0., -1.), -1.)
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for x in [NINF, -1., -0., 0., 1., INF]:
699+
self.assertFalse(math.isnan(x))
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with self.subTest("math.fmin(INF, x)", x=x):
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self.assertEqual(math.fmin(INF, x), x)
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with self.subTest("math.fmin(x, INF)", x=x):
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self.assertEqual(math.fmin(x, INF), x)
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with self.subTest("math.fmin(NINF, x)", x=x):
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self.assertEqual(math.fmin(NINF, x), NINF)
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with self.subTest("math.fmin(x, NINF)", x=x):
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self.assertEqual(math.fmin(x, NINF), NINF)
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@requires_IEEE_754
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def test_fmin_nans(self):
713+
# When exactly one operand is NaN, the other is returned.
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for x in [NINF, -1., -0., 0., 1., INF]:
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with self.subTest(x=x):
716+
self.assertFalse(math.isnan(x))
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self.assertFalse(math.isnan(math.fmin(NAN, x)))
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self.assertFalse(math.isnan(math.fmin(x, NAN)))
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self.assertFalse(math.isnan(math.fmin(NNAN, x)))
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self.assertFalse(math.isnan(math.fmin(x, NNAN)))
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# When operands are NaNs with identical sign, return this signed NaN.
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self.assertTrue(is_signed_nan(math.fmin(NAN, NAN), 1))
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self.assertTrue(is_signed_nan(math.fmin(NNAN, NNAN), -1))
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# When operands are NaNs of different signs, return the negative NaN.
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self.assertTrue(is_signed_nan(math.fmin(NAN, NNAN), -1))
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self.assertTrue(is_signed_nan(math.fmin(NNAN, NAN), -1))
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def testFrexp(self):
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self.assertRaises(TypeError, math.frexp)
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‎Misc/NEWS.d/next/Library/2025-06-24-13-30-47.gh-issue-135853.7ejTvK.rst

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@@ -0,0 +1,2 @@
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Add :func:`math.fmax` and :math:`math.fmin` to get the larger and smaller of
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two floating-point values. Patch by Bénédikt Tran.

‎Modules/clinic/mathmodule.c.h

Lines changed: 107 additions & 1 deletion
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‎Modules/mathmodule.c

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@@ -1214,6 +1214,50 @@ math_floor(PyObject *module, PyObject *number)
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return PyLong_FromDouble(floor(x));
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}
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/*[clinic input]
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math.fmax -> double
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x: double
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y: double
1222+
/
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1224+
Returns the larger of two floating-point arguments.
1225+
1226+
[clinic start generated code]*/
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static double
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math_fmax_impl(PyObject *module, double x, double y)
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/*[clinic end generated code: output=00692358d312fee2 input=0dcf618bb27f98c7]*/
1231+
{
1232+
if (isnan(x) && isnan(y)) {
1233+
double s = copysign(1, x);
1234+
return s == copysign(1, y) ? copysign(NAN, s) : NAN;
1235+
}
1236+< 10ACD /span>
return fmax(x, y);
1237+
}
1238+
1239+
/*[clinic input]
1240+
math.fmin -> double
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1242+
x: double
1243+
y: double
1244+
/
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1246+
Returns the smaller of two floating-point arguments.
1247+
[clinic start generated code]*/
1248+
1249+
static double
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math_fmin_impl(PyObject *module, double x, double y)
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/*[clinic end generated code: output=3d5b7826bd292dd9 input=f7b5c91de01d766f]*/
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{
1253+
if (isnan(x) && isnan(y)) {
1254+
double s = copysign(1, x);
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// return ±NAN if both are ±NAN and -NAN otherwise.
1256+
return copysign(NAN, s == copysign(1, y) ? s : -1);
1257+
}
1258+
return fmin(x, y);
1259+
}
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12171261
FUNC1AD(gamma, m_tgamma,
12181262
"gamma($module, x, /)\n--\n\n"
12191263
"Gamma function at x.",
@@ -4175,7 +4219,9 @@ static PyMethodDef math_methods[] = {
41754219
MATH_FACTORIAL_METHODDEF
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MATH_FLOOR_METHODDEF
41774221
MATH_FMA_METHODDEF
4222+
MATH_FMAX_METHODDEF
41784223
MATH_FMOD_METHODDEF
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MATH_FMIN_METHODDEF
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MATH_FREXP_METHODDEF
41804226
MATH_FSUM_METHODDEF
41814227
{"gamma", math_gamma, METH_O, math_gamma_doc},

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