Shade a wedge/portion of a compass or polar plot?

Hi there!

I'm stumped on a question. I need to plot polar vectors from the origin on a polar axis. I can do this using either polarplot or compass without difficulty.

However I also need to shade a portion of the plot. So for instance, a complete wedge of the plot from 0 -> pi/2 shaded grey instead of background.

I tried to draw an arc, and use patch, but it didn't complete e full wedge.

Any ideas?

Jared

Answer 1

[John Chilleri]

Hello,

I've found fill to be useful in this scenario, although it's slow, and I wouldn't recommend it if you plan to shade many many areas.

If you have the coordinates of the edges as vectors x and y (you'll start and finish at the origin I assume), then you can:

fill(x,y,C)

where C is your desired color.

I put this together real fast for the unit circle from 0 to pi/2:

x = [0 0:.01:1 0];
y = [0 sqrt(1-x(2:end-1).^2) 0];
fill(x,y,[.7 .7 .7])
axis([-1 1 -1 1])

It's colored gray and you can make it more or less detailed by changing the .01 value in the x vector.

Hope this helps!

[Adam Danz]

fill() uses patch() which is not currently supported in polar axes.

R2025a update: patch and surfaces are now supported in polaraxes