# scotch_gotst man page

**gomtst** — compute statistics on sparse matrix orderings

## Synopsis

gotst[options] [gfile] [ofile] [lfile]

## Description

The **gotst** program computes, in a sequential way, statistics on a sparse matrix ordering, such as fill-in, operation count, and separator tree parameters: minimum, maximum, average height and variance of its leaves.

Source graph file *gfile* can only be a centralized graph file. File *ofile* represents the ordering of the symmetric sparse matrix the pattern of which is represented by *gfile*. The resulting statistics are stored in file *lfile*. 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, gtst 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).

Since **gotst** performs sequentially the symbolic factorization of matrix *gfile* in order to compute fill-in and operation count numbers, this program can take a long time or even run out of memory, when applied to very large graphs.

## Options

**-h**Display some help.

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

## Example

Display statistics on ordering brol.ord of graph brol.grf:

$ gotst brol.grf brol.ord

## See Also

**gord**(1), **gtst**(1), **dgord**(1).

Scotch user's manual.

## Author

Francois Pellegrini <francois.pellegrini@labri.fr>