How to create a polar rectangle in Matlab

Please help me determine how to create a polar rectangle (not sure what to call it) in Matlab. The closest I have gotten is using the linspace function for the two arc and a simple line to connect the two arcs. I can't seem to cleanly connect the four line segments to make a continuous shape.

Answer 1

[Star Strider]

I am not certain what you want.

Try this:

theta = linspace(0, 2*pi, 5);

figure(1)
polarplot(theta, ones(size(theta)))

[Ron Beck]

Thanks for the quick response. I see that my hand drawn plot didn't upload. Please see picture to explain further.

[Star Strider]

My pleasure.

It didn’t, so I was left wondering.

Try this:

theta = linspace(3*pi/4, 5*pi/4, 25);
arcrad = [0.25; 0.75];                                      % Arc Radius Vector

figure(1)
polarplot(theta, [arcrad(1)*ones(size(theta)); arcrad(2)*ones(size(theta))], '-k', 'LineWidth',2)
hold on
polarplot([theta([1 end]); theta([1 end])], [arcrad(1)*[1 1]; arcrad(2)*[1 1]], '-k', 'LineWidth',2)
polarplot([theta(1)*[1 1]; theta(1)*[1 1]],  [[0 0]; arcrad(1)*[1 1]], ':k');
polarplot([theta(end)*[1 1]; theta(end)*[1 1]],  [[0 0]; arcrad(1)*[1 1]], ':k');
hold off

The first two polarplot calls plot the ‘rectangle’. The last two polarplot calls plot the dashed/dotted lines from the origin to the inner radius.

Experiment to get different orientations and other variations.

[Star Strider]

Ron Beck’s Answer moved here:

Thank you very much. That is exactly what I was looking for.

[Star Strider]

As always, my pleasure.

If my Answer helped you solve your problem, please Accept it!

[Ron Beck]

One more question, what would be the code to create a circle on the same plot?

[Star Strider]

Add this line between hold on and hold off calls to draw a circle at a radius of 0.5:

polarplot(linspace(0,2*pi,360), 0.5*ones(1,360), '-r')

I chose 360 points. Experiment with fewer points to get the result you want.

[Ron Beck]

perfect

[Star Strider]

As always, my pleasure.