Compute the error function of a number
#include <math.h> double erf ( double x ); float erff ( float x ); long double erfl ( long double x );
The erf(), erff(), and erfl() functions compute the following:
If x is large and the result of erf() is subtracted from 1.0, the results aren't very accurate; use erfc() instead.
This equality is true: erf(-x) = -erf(x)
To check for error situations, use feclearexcept() and fetestexcept():
The value of the error function. If the correct value would cause underflow, a range error occurs, and erf(), erff(), and erfl() return DBL_MIN, FLT_MIN, and LDBL_MIN, respectively.
If x is: | These functions return: |
---|---|
NaN | NaN |
±0 | ±0 |
±Inf | ±1 |
Safety: | |
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Cancellation point | No |
Interrupt handler | No |
Signal handler | No |
Thread | Yes |