Draw circle and ellipse in matrix

Hi all, I am using the following code to draw a circle in a given matrix. However, it only works for a squared matrix, if I change the size of the matrix to something else (for example 90 by 100), it won't work. Please help me out. I am new to MATLAB. Thank you.
nx=100;
ny=100;
domain=ones(nx,ny);
[cols rows]=meshgrid(1:nx,1:ny);
centerX = 40;
centerY = 40
radius = 15
circle = (rows - centerY).^2 + (cols - centerX).^2 <= radius.^2
domain(circle)=2;
imagesc(squeeze(domain(:,:)));
Thanks a lot,

Answers (2)

Modify the third line:
nx=100;
ny=90;
domain=ones(ny,nx);
[cols rows]=meshgrid(1:nx,1:ny);
centerX = 40;
centerY = 40
radius = 15
circle = (rows - centerY).^2 + (cols - centerX).^2 <= radius.^2
domain(circle)=2;
imagesc(domain); % Or keep your original code

1 Comment

That's great, Simon. Is there any alternatives for the third line so that we can simply change the size of the domain without changing the code?. Thank you

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in line 3, do not use
domain=ones(nx,ny);
but use
domain=ones(ny,nx);

1 Comment

Thanks Wan Ji, I am looking for an alternative that can replace the third line, so that we can only need to change the size (input of nx and ny) without changing the code.

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R2021a

Asked:

on 11 Aug 2021

Commented:

on 11 Aug 2021

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