ERF

float erf(float argument)

Returns the error function encountered when integrating the normal distirbution (see normdist).

Mathematically,

Example

=erf(0)

= 0

=erf(1)

» 0.8427

=erf(-1)

» -0.8427 (erf is an odd function)

=erf(107)

returns an error (#VALUE!) since numerical integration overflows for x > 106 or so (the actual erf(x) ® 1 as x ® ¥).