gcv(1)

💅 gcv — graph file converter (from the Scotch user's manual, gcv(1))

okay bestie, listen up, because this one is genuinely so useful and the vibe is immaculate. gcv is the graph file converter from Scotch, and it's about to be your new best friend for moving graphs between formats. 🦋

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✨ SYNOPSIS ✨

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

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🌸 DESCRIPTION 🌸

So what does gcv actually do? It converts Scotch graph files from and to other external file formats. That's it, that's the whole job, and it does it flawlessly. 💖

File igfile is converted into graph file ogfile, with optional geometry data being put in geometry file oxfile, if it is available. (geometry data is a whole optional side quest, love that for us.)

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 '-'. no cap, a single - and she knows exactly what you mean. 💅

When the proper libraries have been included at compile time, gcv 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'). compressed files?? she ate that fr fr. 🔥

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👑 OPTIONS 👑

• -h — Display some help. when you're lost, she's got you. 🫶
• -iifmt — Set format of input graph file, which can be:
  • bnum — 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. (so like, -ib2 would be matrix index 2, iykyk 💀)
  • c — Chaco format. This is an adjacency graph format, also used by MeTiS. iconic crossover moment. ✨
  • 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.
• -oofmt — 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. the main character, as she should be. 👑
• -V — Display program version and copyright.

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🌈 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

look at her go. literal perfection, no notes. 🎀

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🦋 SEE ALSO 🦋

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

Scotch user's manual.

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💜 AUTHOR 💜

Francois Pellegrini <francois.pellegrini@labri.fr>

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not me getting emotional over a manpage, but okay. 💖

that's the whole page, bestie, you're so welcome. ✨ go convert some graphs, slay, periodt. 💅🌸

🍓 gcv(1) — Scotch user's manual — 16 June 2026 🍓