netcdf4 extract for subset of lat lon

Question

I would like to extract a spatial subset of a rather large netcdf file. From Loop through netcdf files and run calculations - Python or R

from pylab import          


        

Answer 1

Small change needs to be made to the lonbounds part (data are degrees east), because the longitude value ranges from 0 to 359 in the data, so negative numbers will not work in this case. Also the calculation for latli and latui needs to be switched because the value goes from north to south, 89 to -89.

latbounds = [ 40 , 43 ]
lonbounds = [ 260 , 270 ] # degrees east
lats = f.variables['latitude'][:] 
lons = f.variables['longitude'][:]

# latitude lower and upper index
latli = np.argmin( np.abs( lats - latbounds[1] ) )
latui = np.argmin( np.abs( lats - latbounds[0] ) ) 

# longitude lower and upper index
lonli = np.argmin( np.abs( lons - lonbounds[0] ) )
lonui = np.argmin( np.abs( lons - lonbounds[1] ) )