---
name: "ncap2"
section: "1"
platform: "linux"
package: "nco"
version: "5.3.3-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/ncap2"
---

# ncap2(1)

netCDF Arithmetic Processor, Next Generation

## NAME

ncap2 - netCDF Arithmetic Processor, Next Generation

## SYNTAX

ncap2 \[-3\] \[-4\] \[-5\] \[-6\] \[-7\] \[-A\] \[--bfr *sz\_byt*\]*\[-C\]*\[-c\]*\[-D* *dbg\_lvl*\] \[-F\] \[--fl\_fmt=fmt\] \[-f\] \[--glb *att\_name=* *att\_val*\]\] \[-H\] \[-h\] \[--hdf\] \[--hdr\_pad *sz\_byt*\]*\[--hpss\_try\]* \[-l  *path*\] \[--no\_tmp\_fl\] \[-O\] \[-o  *output-file*\] \[-p  *path*\] \[-R\] \[-r\] \[--ram\_all\] \[-S  *script-file*\]*\[-s* *script*\]*\[-t* *thr\_nbr*\]*\[--uio\]*\[-v *var*\[,...\]\] *\[ input-file \]* *output-file*

## DESCRIPTION

**ncap2** supersedes 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 \<http://nco.sf.net/ncap2.in\>  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.

## EXAMPLES

Compute the square of variable  **T**

ncap2 -s "T2=T\*T" in.nc out.nc

## AUTHOR

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

## REPORTING BUGS

Report bugs to \<http://sf.net/bugs/?group\_id=3331\>.

## COPYRIGHT

Copyright © 1995-present 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 Users 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 Users 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.

[**ncap2**(1)](/ncap2/1.md), [**ncatted**(1)](/ncatted/1.md), [**ncbo**(1)](/ncbo/1.md), [**ncclimo**(1)](/ncclimo/1.md), [**nces**(1)](/nces/1.md), [**ncecat**(1)](/ncecat/1.md), [**ncflint**(1)](/ncflint/1.md), [**ncz2psx**(1)](/ncz2psx/1.md), [**ncks**(1)](/ncks/1.md), [**nco**(1)](/nco/1.md), [**ncpdq**(1)](/ncpdq/1.md), [**ncra**(1)](/ncra/1.md), [**ncrcat**(1)](/ncrcat/1.md), [**ncremap**(1)](/ncremap/1.md), [**ncrename**(1)](/ncrename/1.md), [**ncwa**(1)](/ncwa/1.md)

## HOMEPAGE

The  **NCO** homepage at \<http://nco.sf.net\> contains more information.