LOG(3) Linux Programmer's Manual LOG(3)[top]NAMElog, logf, logl - natural logarithmic functionSYNOPSIS#include <math.h> double log(double x); float logf(float x); long double logl(long double x); Link withFeature Test Macro Requirements for glibc (see feature_test_macros(7)): logf(), logl(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L; or cc -std=c99-lm.DESCRIPTIONThe log() function returns the natural logarithm of x.RETURN VALUEOn success, these functions return the natural logarithm of x. If x is a NaN, a NaN is returned. If x is 1, the result is +0. If x is positive infinity, positive infinity is returned. If x is zero, then a pole error occurs, and the functions return,-HUGE_VAL, or-HUGE_VALF, respectively. If x is negative (including negative infinity), then a domain error occurs, and a NaN (not a number) is returned.-HUGE_VALLERRORSSee math_error(7) for information on how to determine whether an error has occurred when calling these functions. The following errors can occur: Domain error: x is negative errno is set to EDOM. An invalid floating-point exception (FE_INVALID) is raised. Pole error: x is zero errno is set to ERANGE. A divide-by-zero floating-point excepâ tion (FE_DIVBYZERO) is raised.CONFORMING TOC99, POSIX.1-2001. The variant returning double also conforms to SVr4, 4.3BSD, C89.BUGSIn glibc 2.5 and earlier, taking the log() of a NaN produces a bogus invalid floating-point (FE_INVALID) exception.SEE ALSOcbrt(3), clog(3), log10(3), log1p(3), log2(3), sqrt(3)COLOPHONThis page is part of release 3.65 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/. 2010-09-20 LOG(3)

List of man pages available for

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]

Polar

Member of Polar

Based on Fawad Halim's script.

....................................................................

Vote for polarhome |