The gbase program allows one to set to bval the base value of a source graph, that is, the starting index
used to number its vertices and edges. The base value can be set to 0 or 1, so that graphs can be easily
imported from and/or exported to tools written in C or Fortran. Scotch can handle graphs irrespective of
their base value.
When the proper libraries have been included at compile time, gbase 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').