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

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Jared Saletin on 23 Jan 2017
Commented: Adam Danz on 30 Jul 2020
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

John Chilleri on 23 Jan 2017
Edited: John Chilleri on 23 Jan 2017
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 on 30 Jul 2020
fill() uses patch() which is not currently supported in polar axes.