/* -------------------------------------------------------------------- kernel.c: MEX-file code for evaluation of kernel functions. Compile:  mex kernel.c kernel_fun.c Synopsis:   K = kernel( data, ker, arg )    data [dim x n1] ... Input vectors.    ker [string] ... Kernel identifier (see kernel_fun.c)    arg [1 x nargarg] ... Kernel argument(s).    K [n1 x n1] ... Kernel matrix K[i,j] = kernel(dataA(:,i),dataA(:,j));  K = kernel( dataA, dataB, ker, arg )    dataA [dim x n1] ... Matrix A.    dataB [dim x n2] ... Matrix B.    ker [string] ... Kernel identifier (see kernel_fun.c)    arg [1 x nargarg] ... Kernel argument(s).    K [n1 x n2] ... Kernel matrix K[i,j] = kernel(dataA(:,i),dataB(:,j)); About: Statistical Pattern Recognition Toolbox (C) 1999-2003, Written by Vojtech Franc and Vaclav Hlavac <a href="http://www.cvut.cz">Czech Technical University Prague</a> <a href="http://www.feld.cvut.cz">Faculty of Electrical Engineering</a> <a href="http://cmp.felk.cvut.cz">Center for Machine Perception</a> Modifications: 4-may-2004, VF 21-jan-2002, VF 13-sep-2002, VF 21-October-2001, V.Franc. 30-September-2001, V.Franc, created. -------------------------------------------------------------------- */#include "mex.h"#include "matrix.h"#include <math.h>#include <stdlib.h>#include "kernel_fun.h"/* ============================================================== Main MEX function - interface to Matlab.============================================================== */void mexFunction( int nlhs, mxArray *plhs[],		  int nrhs, const mxArray *prhs[] ){   long i, j, n1, n2;   double tmp;   double *K;     /* K = kernel( data, ker, arg ) */   /* ------------------------------------------- */   if( nrhs == 3)    {      /* data matrix [dim x n1] */      if( !mxIsNumeric(prhs[0]) || !mxIsDouble(prhs[0]) ||        mxIsEmpty(prhs[0])    || mxIsComplex(prhs[0]) )        mexErrMsgTxt("Input data must be a real matrix.");      /* kernel identifier */      ker = kernel_id( prhs[1] );      if( ker == -1 )         mexErrMsgTxt("Improper kernel identifier.");           /*  get pointer to arguments  */     arg1 = mxGetPr(prhs[2]);     /* get pointer at input vectors */     dataA = mxGetPr(prhs[0]);        dataB = dataA;     dim = mxGetM(prhs[0]);           n1 = mxGetN(prhs[0]);            /* creates output kernel matrix. */     plhs[0] = mxCreateDoubleMatrix(n1,n1,mxREAL);     K = mxGetPr(plhs[0]);     /* computes kernel matrix. */     for( i = 0; i < n1; i++ ) {        for( j = i; j < n1; j++ ) {           tmp = kernel( i, j );           K[i*n1+j] = tmp;            K[j*n1+i] = tmp; /* kernel is symetric */        }     }   }    /* K = kernel( dataA, dataB, ker, arg ) */   /* ------------------------------------------- */   else if( nrhs == 4)   {      /* data matrix [dim x n1 ] */      if( !mxIsNumeric(prhs[0]) || !mxIsDouble(prhs[0]) ||        mxIsEmpty(prhs[0])    || mxIsComplex(prhs[0]) )        mexErrMsgTxt("Input dataA must be a real matrix.");      /* data matrix [dim x n2 ] */      if( !mxIsNumeric(prhs[1]) || !mxIsDouble(prhs[1]) ||        mxIsEmpty(prhs[1])    || mxIsComplex(prhs[1]) )        mexErrMsgTxt("Input dataB must be a real matrix.");      /* kernel identifier */      ker = kernel_id( prhs[2] );      if( ker == -1 )         mexErrMsgTxt("Improper kernel identifier.");     /*  get pointer to arguments  */     arg1 = mxGetPr(prhs[3]);     /* pointer at patterns */     dataA = mxGetPr(prhs[0]);         dataB = mxGetPr(prhs[1]);         dim = mxGetM(prhs[0]);            n1 = mxGetN(prhs[0]);             n2 = mxGetN(prhs[1]);             /* creates output kernel matrix. */     plhs[0] = mxCreateDoubleMatrix(n1,n2,mxREAL);     K = mxGetPr(plhs[0]);     /* computes kenrel matrix. */     for( i = 0; i < n1; i++ ) {        for( j = 0; j < n2; j++ ) {           K[j*n1+i] = kernel( i, j );        }     }   }   else   {      mexErrMsgTxt("Wrong number of input arguments.");   }   return;}