php 한글 메뉴얼 도움말 검색 사이트 Returns log(1 + number), computed in a way that is accurate even when [function.log1p]

설명

float log1p ( float $number )

log1p() returns log(1 + number) computed in a way that is accurate even when the value of number is close to zero. log() might only return log(1) in this case due to lack of precision.

인수

number: The argument to process

반환값

log(1 + number)

변경점

버전	설명
5.3.0	This function is now available on all platforms

참고

expm1() - Returns exp(number) - 1, computed in a way that is accurate even when the value of number is close to zero
log() - 자연로그
log10() - 상용로그