www.pudn.com > programradarsystemdisign.zip > factor.m

function [val] = factor(n) 
% Compute the factorial of n using logarithms to avoid overflow. 
format long 
n = n + 9.0; 
n2 = n * n; 
temp = (n-1) * log(n) - n + log(sqrt(2.0 * pi * n)) ... 
   + ((1.0 - (1.0/30. + (1.0/105)/n2)/n2) / 12) / n; 
val = temp - log((n-1)*(n-2)*(n-3)*(n-4)*(n-5)*(n-6) ... 
   *(n-7)*(n-8)); 
return