log1pl (3)

LOG1P(3) Linux Programmer's Manual LOG1P(3) NAME log1p, log1pf, log1pl - logarithm of 1 plus argument SYNOPSIS #include <math.h> double log1p(double x); float log1pf(float x); long double log1pl(long double x); Link with -lm. Feature Test Macro Requirements for glibc (see feature_test_macros(7)): log1p(), log1pf(), log1pl(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 500 || _ISOC99_SOURCE; or cc -std=c99 DESCRIPTION log1p(x) returns a value equivalent to 'log (1 + x)'. It is computed in a way that is accurate even if the value of x is near zero. CONFORMING TO BSD, C99. The float and long double variants are C99 requirements. SEE ALSO exp(3), expm1(3), log(3) 2007-07-26 LOG1P(3)