libsvm2bin.cpp

#include <stdio.h>  
#include <iostream.h>
#include <fstream.h>
#include <vector.h>
#include <math.h>

#include "svqp2/svqp2.h"
#include "svqp2/vector.h"

vector <lasvm_sparsevector_t*> X; // feature vectors
vector <int> Y;                   // labels
int m;                            // number of examples
int sparse=1;
int	max_index = 0;

void libsvm_load_data(char *filename)
// loads the same format as LIBSVM
{ 
    int index; double value;
	int elements, i;
	FILE *fp = fopen(filename,"r");
	lasvm_sparsevector_t* v;
	int splitpos=0;

	if(fp == NULL)
	{
		fprintf(stderr,"Can't open input file \"%s\"\n",filename);
		exit(1);
	}
    else
    printf("\"%s\"..  ",filename);

	int msz = 0;
	elements = 0;
	while(1)
	{
		int c = fgetc(fp);
		switch(c)
		{
			case '\n':
			    v=lasvm_sparsevector_create();
				X.push_back(v); 
				++msz; 
				//printf("%d\n",m);
				elements=0;
				break;  
			case ':':
				++elements;
				break;
			case EOF:
				goto out;
			default:
				;
		}
	}
out:
	rewind(fp);

    
	for(i=0;i<msz;i++)
	{
		int label;
		fscanf(fp,"%d",&label);
		Y.push_back(label);
		while(1) 
		{   
			int c;
			do {
				c = getc(fp);
				if(c=='\n') goto out2;
			} while(char(c)==' ');  //(isspace(c));
			ungetc(c,fp);
			fscanf(fp,"%d:%lf",&index,&value);
		
			lasvm_sparsevector_set(X[m+i],index,value);
			if (index>max_index) max_index=index;
		}	
		out2:
		label=1; // dummy
	}

	fclose(fp); 
	
	m=X.size();
	printf("examples: %d   features: %d\n",m,max_index);
}


void fullbin_save(char *fname)
{	
	int i,j;
	ofstream f;
	f.open(fname,ios::out|ios::binary);

	// write number of examples and number of features
	int sz[2]; sz[0]=m; sz[1]=max_index;
	f.write((char*)sz,2*sizeof(int));
	if (!f) { printf("File writing error in line %d.\n",i); exit(1);}

	float buf[max_index+1]; 
	for(i=0;i<m;i++) 
	{
		sz[0]=Y[i];       // write label
		f.write((char*)sz,1*sizeof(int));

		// write out features for each example
		for(j=0;j<max_index;j++) buf[j]=0;
		lasvm_sparsevector_pair_t *p;
		
		lasvm_sparsevector_foreach(p, X[i]) {
		  if(p->index>max_index)
		    {
		      printf("error! index %d??\n",p->index); exit(1);
		    }
		  buf[p->index]=p->value;
		}
		f.write((char*)buf,max_index*sizeof(float));
	}
	f.close();
}



void bin_save(char *fname)
{	
	int i,j;
	ofstream f;
	f.open(fname,ios::out|ios::binary);

	// write number of examples and a 0 to say that the matrix is sparse
	int sz[2]; sz[0]=m; sz[1]=0;
	f.write((char*)sz,2*sizeof(int));
	if (!f) {printf("File writing error in line %d.\n",i); exit(1);}

	float buf[max_index];
	int   ind[max_index];
	
	for(i=0;i<m;i++)
	{   
	  lasvm_sparsevector_pair_t *p;
	  max_index=0;
	  
	  lasvm_sparsevector_foreach(p, X[i]) {
	    //printf("%d:%g ",p->index,p->value);
	    buf[max_index]=p->value;
	    ind[max_index]=p->index;
	    max_index++;	
	  }
	  
	  sz[0]=Y[i];       // write label
	  sz[1]=max_index;  // write length of example (how many nonsparse entries)
	  f.write((char*)sz,2*sizeof(int));
	  f.write((char*)ind,max_index*sizeof(int));   // write indices
	  f.write((char*)buf,max_index*sizeof(float)); // write values
	  if (!f) {printf("File writing error in line %d.\n",i); exit(1);}
	}
	f.close();
}



int main(int argc, char **argv)  
{
    printf("\n");
    printf("libsvm2bin file converter\n");
    printf("_________________________\n");
    
	if(argc<3 || (argc==3 && strcmp("-F",argv[1])==0))
	{
		printf("usage: %s [-F] <input file> <output file>\n",argv[0]);
		printf("	-F full matrix : forces full rather than sparse matrix storage.\n");
		exit(0);
	}

	if(strcmp(argv[1],"-F")==0)  
	{
		sparse=0;printf("[storing as a full matrix]\n");
		libsvm_load_data(argv[2]);
		fullbin_save(argv[3]);
	}
	else
	{
		libsvm_load_data(argv[1]);
		bin_save(argv[2]);
	}	
}