ncap2(1) netCDF Arithmetic Processor, Next Generation


ncap2 [-3] [-4] [-6] [-7] [-A] [--bfr sz][-C][-c][-D dbg_lvl] [-d dim,[ min][,[ max]]] [-F] [-f] [--glb att_name= att_val]] [-h] [--hdf] [--hdr_pad sz] [-l path] [--no_tmp_fl] [-O] [-o output-file] [-p path] [-R] [-r] [--ram_all] [-S script-file][-s script][-t thr_nbr][-v var[,...]] input-file [ output-file ]


ncap2 supercedes and is backwards-compatible with ncap which is now deprecated. Both operators arithmetically process netCDF files. The primary ncap2 documentation is currently the sample script <> The remainder of this manpage is identical to the ncap manpage.

The processing instructions are contained either in the NCO script file fl.nco or in a sequence of command line arguments. The options -s (or long options --spt or --script) are used for in-line scripts and -S (or long options --fl_spt or --script-file) are used to provide the filename where (usually multiple) scripting commands are pre-stored. ncap2 was written to perform arbitrary albebraic transformations of data and archive the results as easily as possible. Missing values are treated correctly. The results of the algebraic manipulations are called derived fields.

Unlike the other operators, ncap2 does not accept a list of variables to be operated on as an argument to -v. Rather, the -v switch takes no arguments and indicates that ncap2 should output only user-defined variables. ncap2 does not accept or understand the -x switch.


Compute the square of variable T

ncap2 -s "T2=T*T"


NCO manual pages written by Charlie Zender and originally formatted by Brian Mays.


Report bugs to <>.


Copyright © 1995-2016 Charlie Zender
This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.


The NCO homepage at <> contains more information.