Re: [Matplotlib-users] Re-projecting raster data with Basemap

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

Jose Gomez-Dans wrote:
> Jeff,
>
> On Mon, Sep 8, 2008 at 6:48 PM, Jeff Whitaker <js...@fa... 
> <mailto:js...@fa...>> wrote:
>
>     Note that to plot the data with pcolor/pcolormesh of contourf, you
>     don't need to interpolate to a native projection grid.  You can
>     just do
>
>     lons, lats = np.meshgrid(lons,lats)
>     x,y = m(lons,lats)
>     im = m.pcolormesh(x,y,datain)
>
>
> OK, I've gone down the pcolormesh route. Results is very nice. 
> However, if I try to save my file as an EPS or PDF, it takes a long 
> time, and the resulting PDF is 12Mb (!). The equivalent EPS is of the 
> order of 500MB (!!!!), and the PNG is around 100kb (!!!!!). I have a 
> really hard time rendering either the EPS or the PDF, and I guess that 
> using pcolormesh somehow sticks all the pixels into the resulting 
> "page". My image size is around 1000x2500 pixels, and I'm not 
> particularly bothered if it is smoothed for "presentation purposes" 
> (in fact, I think I can see some aliasing, but don't have the plot in 
> front of me right now).
>
> I don't recall this problem when using imshow (no basemap involved). 
> Is this a pcolormesh "feature" (or converseley, an imshow feature?). 
> Is there some I can make my plots be as reasonable as other MPL plots 
> that are mostly vectors rather than rasters?
>
> Cheers,
> J

Jose:  Basemap has nothing to do with it.  I suspect you would see the 
same PDF and EPS sizes with imshow.  I don't know of anyway around it, 
other than using high-resolution PNG files instead of EPS/PDF.

-Jeff

-- 
Jeffrey S. Whitaker         Phone : (303)497-6313
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