function d = pdfnorm(z)
%PDFNORM Probability density function for standard normal distribution.
%
%   D = PDFNORM(Z) returns the probability density for the standard normal
%   distribution function.

%   Author:      Peter J. Acklam
%   Time-stamp:  2003-04-13 11:45:31 +0200
%   E-mail:      pjacklam@online.no
%   URL:         http://home.online.no/~pjacklam

   d = exp(-0.5 * z.^2) / sqrt(2 * pi);