Custom cdo command

You can apply any valid cdo command to the whole ensemble using the my_operator() function. Chained cdo commands are allowed. In this example we will carry out several chained operations. Our objective is to get a time-anomalies of sea-ice for the period 1979 to 2013 relative to a base-period of 1991 to 2000. We also want the result to be zonally meaned, and remapped onto a 1-degree-latitude grid:

import cmipdata as cd

ens = cd.mkensemble('sic_OImon*')

my_cdo_str = 'cdo remapdis,r1x180 -zonmean -seldate,1979-01-01,2013-12-31' +
             '-sub {infile} -timmean -seldate,1991-01-01,2000-12-31 {infile}' +
             '{outfile}'

ens = cd.my_operator(ens, my_cdo_str, output_prefix='test_', delete=False)

The result is a set of files that begin with the prefix ``test_`, and an updated ensemble.