homology.h

Go to the documentation of this file.

// Copyright (C) 1997-2010 by Pawel Pilarczyk.
//
// This file constitutes a part of the Homology Library, 
// distributed under the terms of the GNU General Public License.
// Consult  http://capd.wsb-nlu.edu.pl/ for details. 

// Started on March 19, 2006. Last revision: July 27, 2007.


#ifndef _CAPD_HOMENGIN_HOMOLOGY_H_ 
#define _CAPD_HOMENGIN_HOMOLOGY_H_ 

#include <string>
#include <cstring>
#include "capd/homengin/engines.h"


inline void ComputeBettiNumbers (const void *buffer, int *sizes, int dim,
        int *result, const char *engine = 0, const int *wrapping = 0,
        bool quiet = false)
{
        using namespace chomp::homology;
        // turn off screen output if requested to
        bool soutput = sout. show;
        bool coutput = scon. show;
        if (quiet)
        {
                sout. show = false;
                scon. show = false;
                fcout. turnOff ();
        }
        else
                fcout. turnOn ();

        // create a corresponding set of cubes
        chomp::homengin::cubitmap X (reinterpret_cast<const char *> (buffer),
                sizes, dim);

        // set the space wrapping
        if (wrapping)
                X. setwrapping (wrapping, dim);

        // find the best engine to use for the homology computation
        const chomp::homengin::engine *e;
        if (!engine)
                e = chomp::homengin::engine::find (&X);

        // another possibility: find the engine with the given name
        else
                e = chomp::homengin::engine::find (engine);

        // compute the homology of the set of cubes
        chomp::homengin::algstruct<chomp::homology::integer> hom;
        e -> homology (X, hom);
        sout << "The computed homology is " << hom << ".\n";

        // fill in the resulting table of Betti numbers
        int levels = hom. countLevels ();
        for (int i = 0; i <= dim; ++ i)
                result [i] = (i < levels) ? hom. getBetti (i) : 0;

        // restore the message settings
        chomp::homology::sout. show = soutput;
        chomp::homology::scon. show = coutput;
        return;
} /* ComputeBettiNumbers */


// *** temporarily ***
#include "capd/homengin/cubiset.h"


#endif // _CAPD_HOMENGIN_HOMOLOGY_H_