function fy=tlinear(fx, a, b) 
%  tlinear(fx, a, b)  Generates a probability function fy where Y=g(X), 
%                     g(X)=a*X+b, and X has probability function fx 
if ispf(fx)==0 
   error('not a valid probability function') 
end 
x=xvals(fx); 
p=pvals(fx); 
y=a*x+b; 
fy=[fx(1,:); y' p']; 
P=ttlprob(fy); 
p=p./P; 
fy=[fx(1,:); y' p'];