matlab/dai_potstrength.cpp

   1 /*  Copyright (C) 2006-2008  Joris Mooij  [joris dot mooij at tuebingen dot mpg dot de]
   2     Radboud University Nijmegen, The Netherlands /
   3     Max Planck Institute for Biological Cybernetics, Germany
   4
   5     This file is part of libDAI.
   6
   7     libDAI is free software; you can redistribute it and/or modify
   8     it under the terms of the GNU General Public License as published by
   9     the Free Software Foundation; either version 2 of the License, or
  10     (at your option) any later version.
  11
  12     libDAI is distributed in the hope that it will be useful,
  13     but WITHOUT ANY WARRANTY; without even the implied warranty of
  14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15     GNU General Public License for more details.
  16
  17     You should have received a copy of the GNU General Public License
  18     along with libDAI; if not, write to the Free Software
  19     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  20 */
  21
  22
  23 /*=================================================================*
  24  *                                                                 *
  25  * This is a MEX-file for MATLAB.                                  *
  26  *                                                                 *
  27  *   N = dai_potstrength(psi,i,j);                                 *
  28  *                                                                 *
  29  *=================================================================*/
  30
  31
  32 #include <iostream>
  33 #include "mex.h"
  34 #include <dai/matlab/matlab.h>
  35 #include <dai/factor.h>
  36
  37
  38 using namespace std;
  39 using namespace dai;
  40
  41
  42 /* Input Arguments */
  43
  44 #define PSI_IN          prhs[0]
  45 #define I_IN            prhs[1]
  46 #define J_IN            prhs[2]
  47 #define NR_IN           3
  48
  49
  50 /* Output Arguments */
  51
  52 #define N_OUT           plhs[0]
  53 #define NR_OUT          1
  54
  55
  56 void mexFunction( int nlhs, mxArray *plhs[], int nrhs, const mxArray*prhs[] )
  57 {
  58     long ilabel, jlabel;
  59
  60     // Check for proper number of arguments
  61     if ((nrhs != NR_IN) || (nlhs != NR_OUT)) {
  62         mexErrMsgTxt("Usage: N = dai_potstrength(psi,i,j);\n\n"
  63         "\n"
  64         "INPUT:  psi        = structure with a Member field and a P field, like a CPTAB.\n"
  65         "        i          = label of a variable in psi.\n"
  66         "        j          = label of another variable in psi.\n"
  67         "\n"
  68         "OUTPUT: N          = strength of psi in direction i->j.\n");
  69     }
  70
  71     // Get input parameters
  72     Factor psi = mx2Factor(PSI_IN);
  73     ilabel = (long)*mxGetPr(I_IN);
  74     jlabel = (long)*mxGetPr(J_IN);
  75
  76     // Find variable in psi with label ilabel
  77     Var i;
  78     for( VarSet::const_iterator n = psi.vars().begin(); n != psi.vars().end(); n++ )
  79         if( n->label() == ilabel ) {
  80             i = *n;
  81             break;
  82         }
  83     assert( i.label() == ilabel );
  84
  85     // Find variable in psi with label jlabel
  86     Var j;
  87     for( VarSet::const_iterator n = psi.vars().begin(); n != psi.vars().end(); n++ )
  88         if( n->label() == jlabel ) {
  89             j = *n;
  90             break;
  91         }
  92     assert( j.label() == jlabel );
  93
  94     // Calculate N(psi,i,j);
  95     double N = psi.strength( i, j );
  96
  97     // Hand over result to MATLAB
  98     N_OUT = mxCreateDoubleMatrix(1,1,mxREAL);
  99     *(mxGetPr(N_OUT)) = N;
 100
 101     return;
 102 }