Scotch Brand 5.1.10 - Manual (Page 29)

A brief on-line help is provided with all the programs. To get this help, use the
“-h” option after the program name. The case of option letters is not significant,
except when both the lower and upper cases of a letter have different meanings.
When passing parameters to the programs, only the order of file names is significant;
options can be put anywhere in the command line, in any order. Examples of use
of the different programs of the Scotch project are provided in section 9.
Error messages are standardized, but may not be fully explanatory. However,
most of the errors you may run into should be related to file formats, and located
in “...Load” routines. In this case, compare your data formats with the definitions
given in section 5, and use the gtst and mtst programs to check the consistency of
source graphs and meshes.
6.2 Using compressed files
Starting from version 5.0.6, Scotch allows users to provide and retrieve data in
compressed form. Since this feature requires that the compression and decompres-
sion tasks run in the same time as data is read or written, it can only be done
on systems which support multi-threading (Posix threads) or multi-processing (by
means of fork system calls).
To determine if a stream has to be handled in compressed form, Scotch checks
its extension. If it is “.gz” (gzip format), “.bz2” (bzip2 format) or “.lzma” (lzma
format), the stream is assumed to be compressed according to the corresponding
format. A filter task will then be used to process it accordingly if the format is
implemented in Scotch and enabled on your system.
To date, data can be read and written in bzip2 and gzip formats, and can
also be read in the lzma format. Since the compression ratio of lzma on Scotch
graphs is 30% better than the one of gzip and bzip2 (which are almost equivalent
in this case), the lzma format is a very good choice for handling very large graphs.
To see how to enable compressed data handling in Scotch, please refer to Section 8.
When the compressed format allows it, several files can be provided on
the same stream, and be uncompressed on the fly. For instance, the
command “cat brol.grf.gz brol.xyz.gz | gout -.gz -.gz -Mn - brol.iv”
concatenates the topology and geometry data of some graph brol and feed them
as a single compressed stream to the standard input of program gout, hence the
”-.gz” to indicate a compressed standard stream.
6.3 Description
6.3.1 acpl
Synopsis
acpl [input target file [output target file]] options
Description
The program acpl is the decomposition-defined architecture file compiler. It
processes architecture files of type “deco 0” built by hand or by the amk *
programs, to create a “deco 1” compiled architecture file of about four times
the size of the original one; see section 5.4.1, page 23, for a detailed description
of decomposition-defined target architecture file formats.
The mapper can read both original and compiled architecture file formats.
29