% DFAPPR file dfappr.m Discrete approximation from distribution function
% Version of 10/21/95
% Approximate discrete distribution from distribution
% function entered as a function of t
r = input('Enter matrix [a b] of X-range endpoints  ');
s = input('Enter number of X approximation points  ');
d = (r(2) - r(1))/s;
t = (r(1):d:r(2)-d) +d/2;
m  = length(t);
f  = input('Enter distribution function F as function of t  ');
f  = [0 f];
PX = f(2:m+1) - f(1:m);
PX = PX/sum(PX);
X  = t - d/2;
disp('Distribution is in row matrices X and PX')