Generating parameter search space with vectorized formulation

Vectorized_residuals.m

%%Search parameter space
[xx,yy] = meshgrid([-5:.1:9],[-5:.1:9]);

% Calculate residual for every pair of parameters
%Setup matrix where each row is a single set of parameters
X = [xx(:),yy(:)];
%Calculate residual of each pair of guesses of parameters
res = b-A*X';
r = [];
%Calculate norm^2 of residuals from each guess
for i = 1:length(res)
    r = [r norm(res(:,i))^2];
end
%Reshape back to 2D
phi = reshape(r,size(xx));
%Plot
figure
contour(xx,yy,phi,'ShowText','on')