LOG1P(3) Linux Programmers Manual LOG1P(3)
log1p, log1pf, log1pl - logarithm of 1 plus argument
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
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
BSD, C99. The float and long double variants are C99 requirements.
exp(3), expm1(3), log(3)
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