Re: [Matplotlib-users] Polar plots of radar scans

[Jeff W. <js...@fa...>]

Stephens, A (Ag) wrote:
> Dear all,
>
> I am just looking at matplotlib for the first time and liking very much
> what I see. I have a requirement to try and plot a horizontal scan from
> a radar. The incoming data is simply array(distanceFromInstrument,
> azimuth). Has anybody tried doing for a polar plot without converting
> the data to a lat/lon grid first?
>
> An example of what I'd like to do is visible at:
>
> http://www.chilbolton.rl.ac.uk/weather/latest/latest_ppi_v2.png
>
> Thanks,
>
> Ag
>   
Ag:  You should be able to use either contourf or pcolor to make the 
plot by just passing it the X and Y coordinates of the radial distance, 
azimuth points.  Here's a simple example:

from pylab import *
deltatheta = 2.*pi/100.
theta = arange(0.,2.*pi,deltatheta)
R = arange(0.,pi,deltatheta)
r,t = meshgrid(R, theta)
Z = sin(r)*sin(3.*t)
X = r*cos(t)
Y = r*sin(t)
figure(figsize=(8,8))
cs = contourf(X, Y, Z)
title('Simple polar contour plot')
show()

-Jeff

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