%                    The University of Queensland
%     School of Information Technology & Electrical Engineering
%     ENGG7302 Advanced Computational Techniques in Engineering

% Weighted norm in 2D

W = [1 0; 1 -3];
theta = 2*pi*(0:0.01:1);
V = W * [cos(theta); sin(theta)];
r = sqrt(diag(V' * V)');
fill(cos(theta)./r, sin(theta)./r, [0.5, 0.5, 1]);
axis equal;
axis off;
box off;