/* -------------------------------------------------------------------- kernelproj_mex.c: MEX-file code implementing kernel projection. Compile:  mex kernelproj_mex.c kernel_fun.c Synopsis:   Y = kernelproj_mex(X, Alpha, b, sv_X, ker, arg ) Input:   X [dim x num_data] Vectors to be projected.   Alpha [nsv x new_dim] Multipliers.   b [new_dim x 1] Bias.   sv_X [dim x nsv] Support vectors.   ker [string] Kernel identifier.   arg [1 x narg] Kernel argument. Output:   Y [new_dim x num_data] Projected data. 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: 12-nov-2004, VF 19-sep-2004, VF -------------------------------------------------------------------- */#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, k, m;   long nsv, new_dim, num_data;   double *Alpha;   double *b;   double *Y;   double k_ij;     ker_cnt = 0;   /* Y = kernelproj_mex(X, Alpha, b, sv_X, ker, arg ) */   /* ------------------------------------------- */   if( nrhs == 6)    {      /* data matrix [dim x num_data] */      if( !mxIsNumeric(prhs[0]) || !mxIsDouble(prhs[0]) ||        mxIsEmpty(prhs[0])    || mxIsComplex(prhs[0]) )        mexErrMsgTxt("Input data must be a real matrix.");      /* multipliers Alpha [nsv  x new_dim] */      if( !mxIsNumeric(prhs[1]) || !mxIsDouble(prhs[1]) ||        mxIsEmpty(prhs[1])    || mxIsComplex(prhs[1]) )        mexErrMsgTxt("Input Alpha must be a real matrix.");      /* vector b [nsv  x 1] */      if( !mxIsNumeric(prhs[2]) || !mxIsDouble(prhs[2]) ||        mxIsEmpty(prhs[2])    || mxIsComplex(prhs[2]) )        mexErrMsgTxt("Input b must be a real vector.");      /* kernel identifier */      ker = kernel_id( prhs[4] );      if( ker == -1 )         mexErrMsgTxt("Improper kernel identifier.");           /*  get pointer to arguments  */     arg1 = mxGetPr(prhs[5]);     /* get pointer at input vectors */     dataA = mxGetPr(prhs[0]);        Alpha = mxGetPr(prhs[1]);     b = mxGetPr(prhs[2]);     dataB = mxGetPr(prhs[3]);       /* get data dimensions */      dim = mxGetM(prhs[0]);           num_data = mxGetN(prhs[0]);            nsv = mxGetM(prhs[1]);     new_dim = mxGetN(prhs[1]);     if( mxGetM(prhs[2]) != new_dim)        mexErrMsgTxt("Number of rows of Alpha must equal to size of vector b.");     /* creates output kernel matrix. */     plhs[0] = mxCreateDoubleMatrix(new_dim,num_data,mxREAL);     Y = mxGetPr(plhs[0]);     /* computes kernel projection */     for( i = 0; i < num_data; i++ ) {       for( k = 0; k < new_dim; k++) {          Y[k+i*new_dim] = b[k];        }       for( j = 0; j < nsv; j++ ) {         k_ij = kernel(i,j);         for( k = 0; k < new_dim; k++) {            if(Alpha[j+k*nsv] != 0 )              Y[k+i*new_dim] += k_ij*Alpha[j+k*nsv];          }       }     }   }    else   {      mexErrMsgTxt("Wrong number of input arguments.");   }   return;}