Eric Firing wrote:
> dasratsel wrote:
>
>> Hi,
>>
>> I've done some poking an I can't find a way to use imshow() to plot a
>> luminosity map on a hammer projection. (looking to generate a plot like
>> http://en.wikipedia.org/wiki/Image:WMAP_2008.png). Just setting the
>> projection in a call to subplot gives some axes and an off-center retangular
>> image of my array. Bearing in mind that I am completely new to matplotlib,
>> does anyone have an idea of how to get this sort of plot?
>>
>> Thanks,
>> Kris
>>
>> (PS. Apologies if this shows up in two places, I'm not used to using mailing
>> lists)
>>
>
> Kris,
>
> For any sort of mapping like this, you will probably want to use basemap
> matplotlib toolkit, except that I don't see "hammer" among the supported
> projections.
>
> With straight mpl, imshow does not support projections. You could use
> pcolor (very slow) or pcolormesh. In neither case will you get
> interpolation; you will be specifying colored quadrilaterals.
>
> Eric
>
>
>
Kris: Basemap does not support the 'hammer' projection, but it does
have mollweide, which is very similar. Something like this ought to do it:
from mpl_toolkits.basemap import Basemap
import matplotlib.pyplot as plt
# lon_0 is the center longitude of the data.
map = Basemap(projection='moll',lon_0=180)
# lons, lats are the longitudes and latitudes of the data
# lons.shape, lats.shape = data.shape
x, y = map(lons,lats)
# make a filled mesh plot.
im = map.pcolormesh(x,y,data,cmap=plt.cm.jet)
# draw a boundary around the map
map.drawmapboundary()
plt.show()
-Jeff
--
Jeffrey S. Whitaker Phone : (303)497-6313
NOAA/OAR/CDC R/PSD1 FAX : (303)497-6449
325 Broadway Boulder, CO, USA 80305-3328
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