function P=ttlprob(pf) 
% ttlprob(pf)  sums probability of probability function 
%              better be 1! 
s=size(pf); 
if(isdiscrt(pf)==1) 
   P=0;
   for i=2:s(1), 
      P=P+pf(i,2);
   end 
else 
   s=size(pf); 
   P=trapz(pf(2:s(1),1),pf(2:s(1),2));
end