std::log1p

 

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HUGE_VALFHUGE_VALHUGE_VALL (C++11)(C++11) INFINITY (C++11) NAN (C++11) math_errhandlingMATH_ERRNOMATH_ERREXCEPT (C++11)	FP_NORMALFP_SUBNORMALFP_ZEROFP_INFINITEFP_NAN (C++11)(C++11)(C++11)(C++11)(C++11)

 

Defined in header <cmath>
float       log1p( float arg );		(since C++11)
double      log1p( double arg );		(since C++11)
long double log1p( long double arg );		(since C++11)
double      log1p( Integral arg );		(since C++11)

Computes the natural (base e) logarithm of 1+arg. This function is more precise than the expression std::log(1+arg) if arg is close to zero.

Parameters

arg

-

value of floating-point or Integral type

Return value

ln(1+arg)

Domain error occurs if arg is less than -1. NAN is returned in that case.

Range error occurs if arg is -1. -HUGE_VAL is returned in that case.

See also

log	computes natural (base e) logarithm (to base e) (ln(x)) (function)
expm1 (C++11)	returns e raised to the given power, minus one (ex-1) (function)
log10	computes common (base 10) logarithm (log10(x)) (function)
log2 (C++11)	base 2 logarithm of the given number (function)
C documentation for log1p