log1p - compute a natural logarithm
#include <math.h> double log1p (double x);
The log1p() function computes loge(1.0 + x). The value of x must be greater than -1.0.
Upon successful completion, log1p() returns the natural logarithm of 1.0 + x.If x is NaN, log1p() returns NaN and may set errno to [EDOM].
If x is less than -1.0, log1p() returns -HUGE_VAL or NaN and sets errno to [EDOM].
If x is -1.0, log1p() returns -HUGE_VAL and may set errno to [ERANGE].
The log1p() function will fail if:
- [EDOM]
- The value of x is less than -1.0.
The log1p() function may fail and set errno to:
- [EDOM]
- The value of x is NaN.
- [ERANGE]
- The value of x is -1.0.
No other errors will occur.
None.
None.
None.
log(), <math.h>.