expm1

Date:: 10-12-2011

NAME

expm1, expm1f, expm1l - computes the exponential function minus 1

SYNOPSIS

#include <math.h>

double expm1 (double x)
float expm1f (float x)
long double expm1l (long double x)

IMPLEMENTATION

Cray Linux Environment (CLE)

STANDARDS

C

DESCRIPTION

The expm1, expm1f, expm1l exponential intrinsic functions compute y = ex-1. For small values of x, the expm1 intrinsic is more accurate than exp(x)-1.0.

RETURN VALUES

The expm1, expm1f, expm1l intrinsic functions return one of the following values depending on the value of x:

If x is NaN, the functions return a NaN.
If x is +infinity, the functions return +infinity.
If x is -infinity, the functions return -1.0.
If the result overflows, the functions return +infinity.

Errors

If x is a signaling NaN, an invalid exception is raised.

If the result overflows, an overflow exception is raised.