gausselim.m

A very simple Gaussian elimination code in matlab

function [x] = gaussElim(A,b, verbose)
 N = max(size(A));

 if verbose != 0
   A
   b
 end
 L = zeros(N,N);

 for j=2:N,
   for i=j:N,
     m = myRound(myRound(A(i,j-1))/myRound(A(j-1,j-1)));
     L(i, j-1) = m; 
     for k=1:N,
       A(i,k) = myRound(myRound(A(i,k)) - myRound(myRound(A(j-1,k))*myRound(m)));
     end
     b(i) = myRound(myRound(b(i)) - myRound(m)*myRound(b(j-1)));
     if verbose != 0
       printf("****** Eliminating %d, %d ******\n", i, j-1);
       A
       b
     end
   end
 end

 x = zeros(N,1);
 x(N) = myRound(myRound(b(N))/myRound(A(N,N)));
 
 for j=N-1:-1:1,
   x(j) = myRound(myRound((myRound(b(j))-myRound(A(j,j+1:N)*x(j+1:N))))/myRound(A(j,j)));
 end
 
L=L+eye(N,N)
U=A
A1 = L*U

endfunction