SCL (Star Complement Library) 2.0 - Users Guide

 

 1. Introduction

All this software (written in C++) is covered by the version 2 of the GNU General Public Licence of the Free Software Foundation. Zoran Stanić and Nedeljko Stefanović are the owners of the most of this code. The only exception is the file cliques.cpp. This part is covered by GNU General Public Licence version 2 or any later version published by Free Software Foundation. For more details about ownership of this part read notes from file cliques.cpp.

   The main part of this software is  a library of programs regarding to calculating the maximal graphs using so-called star complement technique. Also, there are two programs (used by the previous library): a program for computing the maximal clique of a given graph, and a program for computing the isomorphism classes of a given family of graphs.

    This is the platform independent version.

 2. The folder structure

The main folder SCL 2.0 contains the executable file scl20 and the file addendum.pdf where the short description of the star complement technique is given. In addition, the main folder contains three subfolders: Source (where the complete source is given), Examples (where some examples for each of programs are given) and Workspace (its subfolders are default places for all input and output files).

    Note, the existence of the folder Workspace (with its subfolders included) in the same folder where the scl20 executable is placed is strongly required! So, if you choose to move the executable file, please include this folder in the same procedure, or use the shortcut of the executable file.

3. Running and using

By simple double-click on the scl20 executable file, or starting it in other way depending of your platform, you will get the following options:

1. Computing the maximal extensions of the star complement
2. Computing the maximal cliques
3. Computing the isomorphism classes of the graphs
4. Exit program

    After you choose the option 1, the program will ask you for the names of the input and output files. The default  filenames are offered. Note, for the files not placed in the folder SCL 2.0/Workspace/Extensions, you must type the file name with the whole path or the file name with relative path to this folder. Otherwise, only the filename is enough. There is only one input file for this program (its default name is input.txt) and only this file is required for running this option (the program creates all output files with names specified).  The input file must contain the adjacency matrix of a star complement followed by an eigenvalue. If the mentioned eigenvalue is not an integer then it must be written with at least 12 (twelve) decimals. In addition, those eigenvalue must not appear in the spectrum of a given graph, and also it must be distinct from 0 and -1 (see addendum). At this point, we recommend consulting the examples if you are using the software for the first time.

    As the output you will get the following four files:

1. Maximal extensions output file (default name: maxext.txt). It contains all maximal extensions of a given star complement for a given eigenvalue followed by their spectra.
2. Good vertices output file (default name: goodvert.txt). It contains all good vertices of a given star complement for a given eigenvalue.
3. E-graph output file (default name: egraph.txt). It contains an extendability graph of a given star complement for a given eigenvalue.
4. Good sets output file (default name: goodsets.txt). It contains all good sets of a given star complement for a given eigenvalue.

    After you choose the option 2, as in the previous case, the program will ask for the names of the input and output files. In this case, there is one input file  (its default name is egraph.txt) as well as one output file (its default name is cliques.txt). The first file must contain the adjacency matrix of an arbitrary graph, while all the maximal cliques of this graph will be written (by the program) in the second file.

    After you choose the option 3, the program will ask you  for the names of the input and the output files. The only input file (its default name is graphs.txt) contains the list of graphs, where each graph has the identification number. The output file (its default name is classes.txt) contains the equivalence classes, their represents with spectra included.

4. Building the executable from the source and installing the software

The complete explanation of this procedure is given in the file README.TXT.