EXP(3) Linux Programmer's Manual EXP(3)

log, logf, logl - natural logarithmic function

#include <math.h>

double log(double x);

float logf(float x);

long double logl(long double x);

Link with -lm.

The log() function returns the natural logarithm of x.

The log() function can return the following errors:

The argument x is negative.
The argument x is zero. The log of zero is not defined (minus infinity).

SVr4, 4.3BSD, C89. The float and the long double variants are C99 requirements.

cbrt(3), clog(3), log1p(3), sqrt(3)

2002-07-27

Different Versions of this Page: