NAME
ncap - netCDF Arithmetic Processor
SYNTAX
ncap [-3] [-4] [-6] [-A] [-C] [-c] [-D dbg] [-F] [-f] [-h] [-L dfl_lvl]
[-l path] [-O] [-o output-file] [-p path] [-R] [-r] [-S script-file][-s
script][-v var[, ... ]] input-file [ output-file ]
DESCRIPTION
ncap arithmetically processes a netCDF file. However, in about 2008
ncap was deprecated in favor of ncap2 which far surpasses its
capbilities. ncap will eventually be completely removed from NCO. It
is currently retained only because it provides an easier-to-build
arithmetic operator than ncap2.
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.
ncap 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, ncap 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 ncap should output only user-defined
variables. ncap does not accept or understand the -x switch.
EXAMPLES
Compute the square of variable T
ncap -s "T2=T*T" in.nc out.nc
AUTHOR
NCO manual pages written by Charlie Zender and Brian Mays.
REPORTING BUGS
Report bugs to <http://sf.net/bugs/?group_id=3331>.
COPYRIGHT
Copyright © 1995-2010 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.
SEE ALSO
The full documentation for NCO is maintained as a Texinfo manual called
the NCO User’s Guide. Because NCO is mathematical in nature, the
documentation includes TeX-intensive portions not viewable on
character-based displays. Hence the only complete and authoritative
versions of the NCO User’s Guide are the PDF (recommended), DVI, and
Postscript versions at <http://nco.sf.net/nco.pdf>,
<http://nco.sf.net/nco.dvi>, and <http://nco.sf.net/nco.ps>,
respectively. HTML and XML versions are available at
<http://nco.sf.net/nco.html> and <http://nco.sf.net/nco.xml>,
respectively.
If the info and NCO programs are properly installed at your site, the
command
info nco
should give you access to the complete manual, except for the TeX-
intensive portions.
HOMEPAGE
The NCO homepage at <http://nco.sf.net> contains more information.