function w = wigner(n,isreal);
%WIGNER The Wigner matrix.
%     WIGNER(N,ISREAL) generates an N x N symettric Wigner matrix.
%     If ISREAL = 1 then the elements of W are real. 
%     If ISREAL = 0 then the elements of W are complex.
%
%     N is an integer while ISREAL equals either 0 or 1.
%     W is an N x N matrix.
% 
%     References:
%     [1] Alan Edelman, Handout 3: Experiments with Classical 
%                       Matrix Ensembles, Fall 2004, 
%                       Course Notes 18.338.
%     [2] Alan Edelman, Random Matrix Eigenvalues.
%     [3] E. P. Wigner, Characteristic vectors of bordered matrices with      
%                       infinite dimensions, Annals of Mathematics,
%                       vol. 62, pages 548-564, 1955.  
%
%     Alan Edelman and Raj Rao, Sept. 2004.
%     $Revision: 1.0 $  $Date: 2004/09/10  23:21:18 $

if(isreal==1)
    g = randn(n,n); 
else
    g = (randn(n,n) + i*randn(n,n))/sqrt(2);
end
   
w = (g + g') / sqrt(2*n);