How to plot level curves

Question

Irene Zhou 2020-11-23

回答： VBBV 2024-8-31

I have an equation Z = exp(-0.5.*((X-800)./40).^2).*cos(2*pi.*Y*1000./X).

I want to plot level curves of Y from -100 to 100 against X from 700 to 900 for Z = -1 to 1. The graph is supposed to look like the one below.

I have tried surf but it's ignoring the axis limits I set. I also don't know how to set Z to different values.

[X,Y] = meshgrid(700:1:900,-100:1:100);

Z = exp(-0.5.*((X-800)./40).^2)*cos(2*pi.*Y*1000./X);

surf(Z)

Any help is appreciated!

Answer 1

VBBV 2024-8-31

@Irene Zhou there is a missing element wise product operator for the equation in your code.

[X,Y] = meshgrid(linspace(700,900,100),linspace(-100,100,100));

Z = exp(-0.5.*((X-800)./40).^2).*cos(2*pi.*Y*1000./X);

% missed a element wise product operator

levels = 50;

contour(X,(Y),Z,levels)

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