MATLAB Answers

Cirle with color changing gradually.

11 views (last 30 days)
How can I plot a circle like this in matlab, please give me an example. Thanks in advance.

Accepted Answer

arich82 on 17 Jul 2015
Edited: arich82 on 17 Jul 2015
[Edited to add colorbar and image.]
As far as I know, you can't do it directly, but pol2cart is your friend. Look at
and maybe
% construct grid of polar coords
th = (0:5:360)*pi/180;
r = 0:.05:1;
[TH, R] = meshgrid(th, r);
% convert polar to cartesian
[X, Y] = pol2cart(TH, R);
% dummy function plotted over X Y data
Z = X + 1i*Y;
f = abs((Z.^4 - 1).^(1/4));
% use overhead view of surf plot for figure
surf(X, Y, f);
axis equal;
axis square;
Note that axis(2) gives an overhead view, so it looks like a flat circle, and axis equal ensures it looks like a circle and not a distorted ellipse.
Please accept this answer if it helps, or let me know what's wrong in the comments.
Walter Roberson
Walter Roberson on 18 Mar 2017
Unfortunately, surf() is not compatible with the new-ish polaraxes (R2016a and later).
You could use the older polar() to create the basic background graphic, and then "hold on", and then plot on top of it.

Sign in to comment.

More Answers (1)

Walter Roberson
Walter Roberson on 18 Mar 2017
The File Exchange contribution transforms rectangular images to and from polar to achieve the effect this Question is about.


Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by