SCL (Star Complement Library) 2.1 - 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.

2. The folder structure

The main folder SCL 2.1 contains the executable file scl21 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). The easiest way to open the folder Workspace is clicking the Workspace button in the main window (see Fig. 1).

Note, the existence of the folder Workspace (with its subfolders included) in the same folder where the scl21 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 scl21 executable file, or starting it in other way depending of your platform, you will get the following window:

Fig. 1

If you choose to compute the maximal extensions of a given star complement and an eigenvalue, then firstly create an input file and navigate to it (its default name is input.txt). 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. Also, the names of all four output files must be given (their default names are given in Fig. 1). After that, by simple click on the Compute button you will get the results. The computation will be followed by some information given in the separate window. After the computation is finished, all results will be saved in the files specified, and also they can be viewed in the separate window by clicking the View File button. The Maximal Extensions output file contains all maximal extensions of a given star complement and an eigenvalue followed by their spectra. The Good Vertices output file contains all good vertices of a given star complement and an eigenvalue. The Extendability Graph output file contains an extendability graph of a given star complement and an eigenvalue. The Good Sets output file contains all good sets of a given star complement and an eigenvalue.

If you choose to compute the maximal cliques of a given graph, then firstly pick that option in the main window. There is one input file as well as one output file (their default names are given in Fig. 2). 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.

Fig. 2

If you choose to compute the isomorphism classes of a given graph set, you should pick that option in the main window. There is one input file as well as one output file (their default names are given in Fig. 3). The first file must contain the list of graphs, where each graph has the identification number. The second file contains the equivalence classes, their represents with spectra included.

Fig. 3

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

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