Tim Michelsen wrote: > Hello Jeff, > > >>>> - Points stored in the above descripbed format (lat, lon, value)? >>>> > This one I solved using a m.scatter() function > > >>>> - Interpolate a grid of data points by using different interpolation >>>> methods like inverse distance wheighting, natural neighbor >>>> > interpolation, etc. to get a contour map? > >>> For interpolation of irregular, randomly distributed data points see >>> http://www.scipy.org/Cookbook/Matplotlib/ >>> > Gridding_irregularly_spaced_data. > >>> However, if there is some structure to the data grid then it's probably >>> better not to use these approaches. >>> > The problem is that although regular spaced the grid is still to large to > countour to a nice map. I will play a bit more with contour and other > interpolation functions. > > I tried griddata: > > >> 2) using the griddata package >> Here I was nearly without orientation how to call griddata correctly. >> > I tried again. > > Here is what I got: > x = data[:,1] > y = data[:,0] > z = data[:,2] > X, Y = mlab.meshgrid(x, y) > X, Z = mlab.meshgrid(x, y) > # zi = griddata(x,y,z,xi,yi,**kwargs) > Z = grid.griddata(x,y,z, X, Y) > plt.contour(X,Y, Z) > > => ValueError: output grid defined by xi,yi must be monotone increasing > > The coordinates are stored in a way that first longitude (x) increases and > then the latitude (y) increases. > 10 6.0 4 > 10 6.25 3 > 10 6.50 2 > 10 6.75 1 > 10 6.0 6 > 11 6.25 7 > 11 6.50 6 > 11 6.75 9 > 12 6.0 4 > > What how do I need to arrange my data to get it monotone increasing for > griddata? > > Thanks for your help. One settled I will send you another example for the > examples package. > > Kind regards, > Timmie > >
Timmie: You shouldn't use griddata. You have a regular lat/lon grid, so it's just a matter of loading the data into the proper 2-d array. Please send a self-contained script (and post the data somewhere) and then we can help you. -Jeff -- Jeffrey S. Whitaker Phone : (303)497-6313 NOAA/OAR/CDC R/PSD1 FAX : (303)497-6449 325 Broadway Boulder, CO, USA 80305-3328 ------------------------------------------------------------------------- Sponsored by: SourceForge.net Community Choice Awards: VOTE NOW! Studies have shown that voting for your favorite open source project, along with a healthy diet, reduces your potential for chronic lameness and boredom. Vote Now at http://www.sourceforge.net/community/cca08 _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
