Issue #3366: Add expm1 function to math module. Thanks Eric Smith for
testing on Windows.
diff --git a/Modules/mathmodule.c b/Modules/mathmodule.c
index b1e4521..469fdf8 100644
--- a/Modules/mathmodule.c
+++ b/Modules/mathmodule.c
@@ -53,6 +53,7 @@
*/
#include "Python.h"
+#include "_math.h"
#include "longintrepr.h" /* just for SHIFT */
#ifdef _OSF_SOURCE
@@ -686,6 +687,10 @@
"cosh(x)\n\nReturn the hyperbolic cosine of x.")
FUNC1(exp, exp, 1,
"exp(x)\n\nReturn e raised to the power of x.")
+FUNC1(expm1, m_expm1, 1,
+ "expm1(x)\n\nReturn exp(x)-1.\n"
+ "This function avoids the loss of precision involved in the direct "
+ "evaluation of exp(x)-1 for small x.")
FUNC1(fabs, fabs, 0,
"fabs(x)\n\nReturn the absolute value of the float x.")
FUNC1(floor, floor, 0,
@@ -1420,6 +1425,7 @@
{"cosh", math_cosh, METH_O, math_cosh_doc},
{"degrees", math_degrees, METH_O, math_degrees_doc},
{"exp", math_exp, METH_O, math_exp_doc},
+ {"expm1", math_expm1, METH_O, math_expm1_doc},
{"fabs", math_fabs, METH_O, math_fabs_doc},
{"factorial", math_factorial, METH_O, math_factorial_doc},
{"floor", math_floor, METH_O, math_floor_doc},