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Still problems... I tried something similar before with meshgrid (how is this different from mgrid?), but I got the same error as below using the method you outline. Is this a function of the 'dateline' issue you mention? My lons go from -180,180 and lats 50,90. I've tried shifting from 0,360 for the lons, but I think the problem is that in projected coordinates I don't have a monotonically increasing x. 170 171 # interpolate on projected grid --> 172 Z0 = mlab.griddata(x, y, z, grid_x, grid_y) 173 /wrk/bin64/site-packages/matplotlib/mlab.py in griddata(x, y, z, xi, yi, interp) 2700 yo = yi.astype(np.float) 2701 if min(xo[1:]-xo[0:-1]) < 0 or min(yo[1:]-yo[0:-1]) < 0: -> 2702 raise ValueError, 'output grid defined by xi,yi must be monotone increasing' 2703 # allocate array for output (buffer will be overwritten by nagridd) 2704 zo = np.empty((yo.shape[0],xo.shape[0]), np.float) ValueError: output grid defined by xi,yi must be monotone increasing And my code: 161 x,y = m(lon,lat) 162 # create your lon-lat grid in degrees using e.g. np.mgrid 163 # you might need to be careful doing this step 164 # if your grid straddles the international dateline 165 grid_lon, grid_lat = np.mgrid[lon.min():lon.max():dres, 166 lat.min():lat.max():dres] 167 168 # find the projected co-ordinates for the grid 169 grid_x, grid_y = m(grid_lon.ravel(), grid_lat.ravel()) 170 171 # interpolate on projected grid 172 Z0 = mlab.griddata(x, y, z, grid_x, grid_y) is my code: Scott Sinclair-4 wrote:
# create your lon-lat grid in degrees using e.g. np.mgrid # you might need to be careful doing this step # if your grid straddles the international dateline grid_lon, grid_lat = np.mgrid[min_lon:max_lon:0.5, min_lat:max_lat:0.5]
# find the projected co-ordinates for the grid grid_x, grid_y = m(grid_lon.ravel(), grid_lat.ravel())
# interpolate on projected grid Znew = mlab.griddata(x, y, z, grid_x, grid_y) Cheers, Scott _______________________________________________ SciPy-User mailing list SciPy-User@scipy.org http://mail.scipy.org/mailman/listinfo/scipy-user
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