To create a mesh plot in MATLAB similar to this -

do the following.

- Initialize vectors X and Y with the x- and y-coordinates.

- For each pair of (x,y) values, compute the function value f(x,y), and store in matrix Z having the form -

Z(2,:) = [ f(y2,x1) f(y2,x2) ... f(y2,xn) ]

and so on.

- Run mesh(X,Y,Z) to the mesh plot.

E.g. Plot f(x,y) = 2x^2 + 12 xy + 7y^2 (shown in plot)

The code will look something like this -

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X = -1:.1:1;

Y=X;

% x's along columns

Xsq = X.*X;

for n=1:size(Y,2)

XsqM(n,:) = Xsq;

end

% y's along rows

Ysq = Y.*Y;

for n=1:size(X,2)

YsqM(:,n) = Ysq';

end

% x's change along a row (y fixed)

% y's change along a col (x fixed)

XY = Y'*X;

Z = 2.*XsqM + 12.*XY - 1.*YsqM;

mesh(X,Y,Z)

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