mexgramsvmtrain.cpp

一个包含丰富内容的流形学习算法工具包

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include "svm.h"
#include "mex.h"

#define Malloc(type,n) (type *)malloc((n)*sizeof(type))

/* Input Arguments */
#define SAMPLES prhs[0]
#define LABELS  prhs[1]
#define PARAMETERS prhs[2]
/* Output Arguments */
#define ALPHAY plhs[0]
#define SVs    plhs[1]
#define BIAS   plhs[2]
#define NSV        plhs[3]
#define NLABEL     plhs[4]




static void parse_command_line(double params[]);
static void read_problem(double examples[], double labels[],int dim, int num);



struct svm_parameter param;		// set by parse_command_line
struct svm_problem prob;		// set by read_problem
struct svm_model *model;
struct svm_node *x_space;







/* int main(int argc, char **argv) */
void mexFunction( int nlhs, mxArray *plhs[], int nrhs, const mxArray*prhs[] )
{
  double *parameters;
  double *labels;
  double *samples;
  int dimension;
  int numberofexamples;
  int l, n;

        parameters = mxGetPr(PARAMETERS); 
	parse_command_line(parameters);

        dimension = mxGetN(SAMPLES);
        numberofexamples = mxGetM(SAMPLES);

        samples = mxGetPr(SAMPLES);
        labels  = mxGetPr(LABELS);
 
	read_problem(samples,labels,dimension,numberofexamples);

	model = svm_train(&prob,&param);

        l=get_svm_model_l(model);
	n=get_svm_model_nrclass(model);

	ALPHAY = mxCreateDoubleMatrix(n-1, l, mxREAL);
	SVs    = mxCreateDoubleMatrix( 1,l, mxREAL);
        BIAS   = mxCreateDoubleMatrix( 1,n*(n-1)/2, mxREAL);
        NSV    =  mxCreateDoubleMatrix( 1,n, mxREAL);
        NLABEL    = mxCreateDoubleMatrix( 1,n, mxREAL);

	svm_copy_model(mxGetPr(ALPHAY),mxGetPr(SVs),mxGetPr(BIAS),mxGetPr(NSV),mxGetPr(NLABEL),model);


	//svm_destroy_model(model);
		

	free(prob.y);
	free(prob.x);
	free(x_space);


}



static void parse_command_line(double params[])
{

	// default values
	param.svm_type = (int) params[7];
	param.kernel_type = MATRIX;
	param.degree = params[1];
	param.gamma = params[2];	// 1/k
	param.coef0 = params[3];
	param.nu = params[8];
	param.cache_size = params[5];
	param.C = params[4];
	param.eps = params[6];
	param.p = params[9];
	param.shrinking = (int) params[10];
	param.nr_weight = 0;
	param.weight_label = NULL;
	param.weight = NULL;

}


// read in a problem (in svmlight format)

static void read_problem(double examples[], double labels[],int dim, int num)
{
  int elements;
  int i,j,p,t;
		
	prob.l = num;
	prob.y = Malloc(double,prob.l);
	prob.x = Malloc(struct svm_node *,prob.l);
	elements=dim*num;
	
	x_space = Malloc(struct svm_node,prob.l + elements );
	
	
	
	
        j=0;
        p=0;

	for(i=0;i<prob.l;i++)
	{
		double label;
		prob.x[i] = &x_space[j];
		prob.y[i] = labels[i];
		
		 x_space[j].index = 1; 
		 x_space[j].value = i+1;
		 j++;
		 for(t=0;t<dim;t++)
		   {
                     x_space[j].index=t+2;
		     x_space[j].value=examples[p];
                     j++;
		     p++;
		   }


                
		
	
		 
                
	}
}