gcv(1) | Scotch user's manual | gcv(1) |

# NAME¶

**gcv**- graph file converter

# SYNOPSIS¶

gcv[options] [igfile] [ogfile] [oxfile]

# DESCRIPTION¶

The**gcv**program converts Scotch graph files from and to other external file formats.

File *igfile* is converted into graph file *ogfile*,
with optional geometry data being put in geometry file *oxfile*, if it
is available.

When file names are not specified, data is read from standard input and written to standard output. Standard streams can also be explicitly represented by a dash '-'.

When the proper libraries have been included at compile time, dgtst can directly handle compressed graphs, both as input and output. A stream is treated as compressed whenever its name is postfixed with a compressed file extension, such as in 'brol.grf.bz2' or '-.gz'. The compression formats which can be supported are the bzip2 format ('.bz2'), the gzip format ('.gz'), and the lzma format ('.lzma', on input only).

# OPTIONS¶

**-h**- Display some help.
**-i**?*ifmt*- Set format of input graph file, which can be:

**b?***num*- Boeing-Harwell format. This is a matrix format. Only square matrices are
supported. Square matrices with unsymmetric pattern are symmetrized. In
case the file contains several matrices, the
*num*parameter allow the user to provide the index of the matrix to convert, starting from 0. When the*num*parameter is not set, it is assumed to be 0. **c**- Chaco format. This is an adjacency graph format, also used by MeTiS.
**m**- Matrix Market format. This is a matrix format describing individual edges. Matrix pattern is symmetrized, such that rectangular matrices are eventually squared.
**s**- Scotch graph format. This is an adjacency graph format.

**-o**?*ofmt*- Set format of output graph file, which can be:

**c**- Chaco format.
**m**- Matrix Market symmetric pattern format.
**s**- Scotch format. This is the default.

**-V**- Display program version and copyright.

# EXAMPLE¶

Convert a Matrix Market graph into a Scotch graph. Matrix Market files do not comprise geometry data, so no geometry file is needed on output:$ gcv -im brol.mm brol.grf

# SEE ALSO¶

gtst(1),**gmap**(1), gord(1), gout(1).

Scotch user's manual.

# AUTHOR¶

Francois Pellegrini <francois.pellegrini@labri.fr>August 3, 2010 |