std::log1p

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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.

[edit] Parameters

arg

-

floating point value

[edit] Return value

ln(1+arg)

Domain error occurs if arg is negative. NAN is returned in that case.

Range error occurs if arg is ​0​. -HUGE_VAL is returned in that case.

[edit] See also

log	computes natural (base e) logarithm (to base e) (ln(x)) (function)
log10	computes common (base 10) logarithm (log10(x)) (function)