Re: [Matplotlib-users] it is possible to use basemap to create regular spaced lat/lon grids?

Hi Aman,
thanks for your code. I am testing it right now, but i think this might
what i need.
Not sure if you know this: what is the difference between:
1) scipy.interpolate.griddata
2) matplotlib.mlab.griddata

For 2) you have specify the interpolation method and i think the calling
convention is different. Is one a wrapper for the other?

thanks
matt


On 9/6/2011 12:36 PM, Aman Thakral wrote:
> Hi Matt,
>
> Something like this?:
>
> def create_map(ax, llcrnrlon,llcrnrlat,urcrnrlon,urcrnrlat):
>     m =
> Basemap(llcrnrlon=llcrnrlon,llcrnrlat=llcrnrlat,urcrnrlon=urcrnrlon,urcrnrlat=urcrnrlat,resolution='i',projection='cyl',lon_0=(urcrnrlon+llcrnrlon)/2,lat_0=(urcrnrlat+llcrnrlat)/2)
>     m.drawcoastlines()
>     m.drawmapboundary()
>     m.drawstates(linewidth=3)
>     m.fillcontinents(color='lightgrey',lake_color='white')
>     m.drawcountries(linewidth=3)
>     return m
>
>
> def plotMapData(ax,data):
>
>     lats = []
>     lons = []
>     val = []
>   
>     for k,v in data.iteritems():
>         lats.append(float(k[0]))
>         lons.append(float(k[1]))
>         val.append(float(v))
>       
>     value = np.array(val)
>     lat = np.array(lats)
>     lon = np.array(lons)
>            
>     llcrnlon = lon.min()-0.5
>     llcrnlat = lat.min()-0.5
>     urcrnlon = lon.max()+0.5
>     urcrnlat = lat.max()+0.5
>
>     xi = np.linspace(llcrnlon,urcrnlon,1000)
>     yi = np.linspace(llcrnlat,urcrnlat,1000)
>     zi = griddata(lon,lat,value,xi,yi)
>
>     cmap = cm.jet
>     m = create_map(ax,llcrnlon,llcrnlat,urcrnlon,urcrnlat)
>     cs = ax.contour(xi,yi,zi,15,linewidth=0.5,cmap=cmap,alpha=0.5)   
>     ax.contourf(xi,yi,zi,15,cmap=cmap,zorder=1000,alpha=0.5)
>
>     colorscale = cm.ScalarMappable()
>     colorscale.set_array(value)
>     colorscale.set_cmap(cmap)
>
>     colors = colorscale.to_rgba(value)
>     ax.scatter(lon,lat,c=colors,zorder=1000,cmap=cmap,s=10)
>     colorbar(colorscale, shrink=0.50, ax=ax,extend='both')
>    
>
> On Tue, Sep 6, 2011 at 1:28 PM, Matt Funk <mat...@gm...
> <mailto:mat...@gm...>> wrote:
>
>     Hi,
>     i want to interpolate irregular spaced satellite data onto a regular
>     spaced grid. The regular spaced grid should have cell sizes of
>     1km^2. Is
>     it possible to use basemap to create such a grid. It looked like it
>     includes some facilities like that, but i am not sure if they are
>     meant
>     to be used by end user or more like internal fcns (the makegrid
>     fcn for
>     example).
>
>     Any advice would be appreciated.
>
>     thanks
>     matt
>
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-- 
Matt Funk
Research Associate
Plant and Environmental Scienc. Dept.
New Mexico State University