On Thursday, January 20, 2011, Jeff Whitaker <jsw...@fastmail.fm> wrote: > On 1/20/11 2:31 PM, R. Mitra wrote: >> Hi >> I have a set of records with known lat long. I want to show the >> concentration of the records with a contour diagram on a world map in >> any projection. It cannot spill over to the oceans. I know I have to >> use basemap. Is there a quick recipe somewhere I can follow to give >> me a desired output. I have gone through earlier posts on this board >> but cannot find the right one. Any pointers would be very helpful. >> Many thanks. >> Best >> Mitra > > > Mitra: The basic procedure is this: > > 1) load you data into 2d numpy arrays (lats, lons, data). lats and lons > must be in degrees (not radians). > 2) create a Basemap instance (called "map") for the desired projection. > 3) calculate the map projection coordinates of your grid with x,y = > map(lons,lats) > 4) contour your data with the contourf method (map.contourf). > 5) draw coastlines with the coastlines method. > 6) draw lat/lon lines with the drawparallels and drawmeridians methods. > > There are many examples of this in the basemap examples directory. > > -Jeff > > ------------------------------------------------------------------------------ > Special Offer-- Download ArcSight Logger for FREE (a $49 USD value)! > Finally, a world-class log management solution at an even better price-free! > Download using promo code Free_Logger_4_Dev2Dev. Offer expires > February 28th, so secure your free ArcSight Logger TODAY! > http://p.sf.net/sfu/arcsight-sfd2d > _______________________________________________ > Matplotlib-users mailing list > Matplotlib-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/matplotlib-users >
In order to contour, you will need some sort z-value to contour. This means you need to bin your data. You could use numpy's hist2d, or (I prefer) matplotlib's hexbin(). I hope that helps! Ben Root ------------------------------------------------------------------------------ Special Offer-- Download ArcSight Logger for FREE (a $49 USD value)! Finally, a world-class log management solution at an even better price-free! Download using promo code Free_Logger_4_Dev2Dev. Offer expires February 28th, so secure your free ArcSight Logger TODAY! http://p.sf.net/sfu/arcsight-sfd2d _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
