! Copyright (C) 2011 John Benediktsson
-! See http://factorcode.org/license.txt for BSD license
+! See https://factorcode.org/license.txt for BSD license
USING: combinators kernel locals math math.constants
math.functions sequences ;
PRIVATE>
! Standalone error function erf(x)
-! http://www.johndcook.com/blog/2009/01/19/stand-alone-error-function-erf/
+! https://www.johndcook.com/blog/2009/01/19/stand-alone-error-function-erf/
:: erf ( x -- value )
x 0 >= 1 -1 ? :> sign
x abs :> x!