ERF intrinsic function
Standard: F77 F90 F95 F2003 F2008 Example Program
ERF ( X )

X : Real;

Result : Same type and kind as X.
The value of the result is an approximation to the “error function” of X; that is 2/SQRT(π) times the integral from 0 to X of et**2dt. Like many intrinsic functions, this is elemental; the result has the same shape as X, with the operation being applied elementwise.

This function converges to 1.0 extremely rapidly with increasing X.

ERFC intrinsic function, ERFC_SCALED intrinsic function.