Plotting non-rectangular data on maps

Orion Poplawski wrote:

Jeff Whitaker wrote:

Orion Poplawski wrote:

I've got a 2-D array of values that I'd like to plot onto a map with Basemap. The latitude and longitudes for each point are stored in their own 2-D array that matches that of the values. Can some one help with how to do this? Looks like basemap requires a square and uniform set of data to plot?

Orion: There's an example of this in the examples directory called 'ccsm_popgrid.py'. Have a look at that, and if you have questions let us know.

Actually, it looks like I may have been making things harder than I thought they would be. Is there any reason to believe that this isn't doing what it seems like it should? ccsm_popgrid.py seems much more complicated, and I'm don't really understand it yet.

tpxyzo has data for 12 different altitudes, and I'm selecting one. It appears the x,y=m(lon,lat) is unneeded for cylindrical projections, but I've left it in here as a general case.

--
from matplotlib.toolkits.basemap import Basemap
from pylab import *

lat=load('lat.dat').reshape(270,90)
lon=load('lon.dat').reshape(270,90)
tpxyzo=load('tpxyzo.dat').reshape(12,270,90)

m=Basemap(llcrnrlon=-80,llcrnrlat=-75,urcrnrlon=-40,urcrnrlat=-42,projection='cyl',resolution='l')

m.drawcoastlines()
x, y = m(lon,lat)
m.contourf(x,y,tpxyzo[11,:,:],15)
show()
--

The output is the attached image, which as you can see does not have a rectangular shape.

Thanks!

Orion: If the image were rectangular on a cylindrical projection, then you wouldn't need 2d arrays to describe the lats and lons of the grid. Are you sure the image should be rectangular? What kind of a grid is it?

-Jeff

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