testing stride on NOMADS

Trying to figure out why this NCO ncks stride command doesn't work:

ncks -O -D4 -d time,1 -d lev,0 -d lat,0,100,3 -d lon,0,100,3 -v u_velocity,v_velocity \
 http://nomads.ncep.noaa.gov:9090/dods/rtofs/rtofs_global20140303/rtofs_glo_2ds_forecast_daily_prog foo.nc

Does it work with netCDF4-Python, which also uses the NetCDF-C library?



In [1]:

    
import netCDF4



In [2]:

    
url='http://nomads.ncep.noaa.gov:9090/dods/rtofs/rtofs_global20140303/rtofs_glo_2ds_forecast_daily_prog'



In [3]:

    
nc = netCDF4.Dataset(url)



In [4]:

    
ncv = nc.variables

Try just reading a few values of longitude



In [5]:

    
ncv['lon'][:10]









    Out[5]:





array([ 74.16   ,  74.24333,  74.32666,  74.40999,  74.49332,  74.57665,
        74.65998,  74.74331,  74.82664,  74.90997])

Now try reading the u_velocity variable with stride



In [6]:

    
u = ncv['u_velocity'][0,0,0:100:3,0:100:3]
v = ncv['v_velocity'][0,0,0:100:3,0:100:3]
print shape(u)
print shape(v)









    



(34, 34)
(34, 34)

Seems to work fine. Why doesn't NCO work?



In [6]: