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Inversion
Posted:
May 19, 2010 9:08 AM


Hi everyone i need help to understand how these codes making inverse on MatLab.It's using Gauss Jordan methode but i couldnt get how it does.I'll be grateful if you could show me on 2*2 Matrix. Thanks Here the link http://www.matrixlabexamples.com/matrixinversion.html
and codes
function b = mat_inv2(a) % Find dimensions of input matrix [r,c] = size(a);
% If input matrix is not square, stop function if r ~= c disp('Only Square Matrices, please') b = []; return end
% Target identity matrix to be transformed into the output % inverse matrix b = eye(r);
%The following code actually performs the matrix inversion for j = 1 : r for i = j : r if a(i,j) ~= 0 for k = 1 : r s = a(j,k); a(j,k) = a(i,k); a(i,k) = s; s = b(j,k); b(j,k) = b(i,k); b(i,k) = s; end t = 1/a(j,j); for k = 1 : r a(j,k) = t * a(j,k); b(j,k) = t * b(j,k); end for L = 1 : r if L ~= j t = a(L,j); for k = 1 : r a(L,k) = a(L,k) + t * a(j,k); b(L,k) = b(L,k) + t * b(j,k); end end end end break end % Display warning if a row full of zeros is found if a(i,j) == 0 disp('Warning: Singular Matrix') b = 'error'; return end end % Show the evolution of the input matrix, so that we can % confirm that it became an identity matrix. a



