www.pudn.com > Gngauss.rar > Variance.m, change:1994-07-24,size:626b


function v=variance(funfcn,a,b,tol,p1,p2,p3) 
% EXPECTED Finds the variance of a random variable  
%	   with probability density function 'funfcn' and  
%	   support [a,b]. 
% 	   Y=VARIANCE('F',A,B,TOL,P1,P2,P3), finds the variance  
% 	   of the density function F defined in an m-file. The 
% 	   function can contain up to three parameters,P1,P2,P3. 
%	   tol=the relative error. 
 
args=[]; 
for n=1:nargin-4 
  args=[args,',p',int2str(n)]; 
end 
args=[args,')']; 
funfcn1=['x.*',funfcn]; 
e=eval(['quad(funfcn1,a,b,tol,[]',args]); 
newfun=['(x-(',num2str(e),')).^2.*',funfcn]; 
v=eval(['quad(newfun,a,b,tol,[]',args]);