#include <float.h>
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <string.h>
void exit_with_help()
{
printf(
"Usage: svm-scale [options] data_filename\n"
"options:\n"
"-l lower : x scaling lower limit (default -1)\n"
"-u upper : x scaling upper limit (default +1)\n"
"-y y_lower y_upper : y scaling limits (default: no y scaling)\n"
"-s save_filename : save scaling parameters to save_filename\n"
"-r restore_filename : restore scaling parameters from restore_filename\n"
);
exit(1);
}
char *line = NULL;
int max_line_len = 1024;
double lower=-1.0,upper=1.0,y_lower,y_upper;
int y_scaling = 0;
double *feature_max;
double *feature_min;
double y_max = -DBL_MAX;
double y_min = DBL_MAX;
int max_index;
long int num_nonzeros = 0;
long int new_num_nonzeros = 0;
#define max(x,y) (((x)>(y))?(x):(y))
#define min(x,y) (((x)<(y))?(x):(y))
void output_target(double value);
void output(int index, double value);
char* readline(FILE *input);
int main(int argc,char **argv)
{
int i,index;
FILE *fp, *fp_restore = NULL;
char *save_filename = NULL;
char *restore_filename = NULL;
for(i=1;i<argc;i++)
{
if(argv[i][0] != '-') break;
++i;
switch(argv[i-1][1])
{
case 'l': lower = atof(argv[i]); break;
case 'u': upper = atof(argv[i]); break;
case 'y':
y_lower = atof(argv[i]);
++i;
y_upper = atof(argv[i]);
y_scaling = 1;
break;
case 's': save_filename = argv[i]; break;
case 'r': restore_filename = argv[i]; break;
default:
fprintf(stderr,"unknown option\n");
exit_with_help();
}
}
if(!(upper > lower) || (y_scaling && !(y_upper > y_lower)))
{
fprintf(stderr,"inconsistent lower/upper specification\n");
exit(1);
}
if(restore_filename && save_filename)
{
fprintf(stderr,"cannot use -r and -s simultaneously\n");
exit(1);
}
if(argc != i+1)
exit_with_help();
fp=fopen(argv[i],"r");
if(fp==NULL)
{
fprintf(stderr,"can't open file %s\n", argv[i]);
exit(1);
}
line = (char *) malloc(max_line_len*sizeof(char));
#define SKIP_TARGET\
while(isspace(*p)) ++p;\
while(!isspace(*p)) ++p;
#define SKIP_ELEMENT\
while(*p!=':') ++p;\
++p;\
while(isspace(*p)) ++p;\
while(*p && !isspace(*p)) ++p;
/* assumption: min index of attributes is 1 */
/* pass 1: find out max index of attributes */
max_index = 0;
if(restore_filename)
{
int idx, c;
fp_restore = fopen(restore_filename,"r");
if(fp_restore==NULL)
{
fprintf(stderr,"can't open file %s\n", restore_filename);
exit(1);
}
c = fgetc(fp_restore);
if(c == 'y')
{
readline(fp_restore);
readline(fp_restore);
readline(fp_restore);
}
readline(fp_restore);
readline(fp_restore);
while(fscanf(fp_restore,"%d %*f %*f\n",&idx) == 1)
max_index = max(idx,max_index);
rewind(fp_restore);
}
while(readline(fp)!=NULL)
{
char *p=line;
SKIP_TARGET
while(sscanf(p,"%d:%*f",&index)==1)
{
max_index = max(max_index, index);
SKIP_ELEMENT
num_nonzeros++;
}
}
rewind(fp);
feature_max = (double *)malloc((max_index+1)* sizeof(double));
feature_min = (double *)malloc((max_index+1)* sizeof(double));
if(feature_max == NULL || feature_min == NULL)
{
fprintf(stderr,"can't allocate enough memory\n");
exit(1);
}
for(i=0;i<=max_index;i++)
{
feature_max[i]=-DBL_MAX;
feature_min[i]=DBL_MAX;
}
/* pass 2: find out min/max value */
while(readline(fp)!=NULL)
{
char *p=line;
int next_index=1;
double target;
double value;
sscanf(p,"%lf",&target);
y_max = max(y_max,target);
y_min = min(y_min,target);
SKIP_TARGET
while(sscanf(p,"%d:%lf",&index,&value)==2)
{
for(i=next_index;i<index;i++)
{
feature_max[i]=max(feature_max[i],0);
feature_min[i]=min(feature_min[i],0);
}
feature_max[index]=max(feature_max[index],value);
feature_min[index]=min(feature_min[index],value);
SKIP_ELEMENT
next_index=index+1;
}
for(i=next_index;i<=max_index;i++)
{
feature_max[i]=max(feature_max[i],0);
feature_min[i]=min(feature_min[i],0);
}
}
rewind(fp);
/* pass 2.5: save/restore feature_min/feature_max */
if(restore_filename)
{
/* fp_restore rewinded in finding max_index */
int idx, c;
double fmin, fmax;
if((c = fgetc(fp_restore)) == 'y')
{
fscanf(fp_restore, "%lf %lf\n", &y_lower, &y_upper);
fscanf(fp_restore, "%lf %lf\n", &y_min, &y_max);
y_scaling = 1;
}
else
ungetc(c, fp_restore);
if (fgetc(fp_restore) == 'x') {
fscanf(fp_restore, "%lf %lf\n", &lower, &upper);
while(fscanf(fp_restore,"%d %lf %lf\n",&idx,&fmin,&fmax)==3)
{
if(idx<=max_index)
{
feature_min[idx] = fmin;
feature_max[idx] = fmax;
}
}
}
fclose(fp_restore);
}
if(save_filename)
{
FILE *fp_save = fopen(save_filename,"w");
if(fp_save==NULL)
{
fprintf(stderr,"can't open file %s\n", save_filename);
exit(1);
}
if(y_scaling)
{
fprintf(fp_save, "y\n");
fprintf(fp_save, "%.16g %.16g\n", y_lower, y_upper);
fprintf(fp_save, "%.16g %.16g\n", y_min, y_max);
}
fprintf(fp_save, "x\n");
fprintf(fp_save, "%.16g %.16g\n", lower, upper);
for(i=1;i<=max_index;i++)
{
if(feature_min[i]!=feature_max[i])
fprintf(fp_save,"%d %.16g %.16g\n",i,feature_min[i],feature_max[i]);
}
fclose(fp_save);
}
/* pass 3: scale */
while(readline(fp)!=NULL)
{
char *p=line;
int next_index=1;
double target;
double value;
sscanf(p,"%lf",&target);
output_target(target);
SKIP_TARGET
while(sscanf(p,"%d:%lf",&index,&value)==2)
{
for(i=next_index;i<index;i++)
output(i,0);
output(index,value);
SKIP_ELEMENT
next_index=index+1;
}
for(i=next_index;i<=max_index;i++)
output(i,0);
printf("\n");
}
if (new_num_nonzeros > num_nonzeros)
fprintf(stderr,
"WARNING: original #nonzeros %ld\n"
" new #nonzeros %ld\n"
"Use -l 0 if many original feature values are zeros\n",
num_nonzeros, new_num_nonzeros);
free(line);
free(feature_max);
free(feature_min);
fclose(fp);
return 0;
}
char* readline(FILE *input)
{
int len;
if(fgets(line,max_line_len,input) == NULL)
return NULL;
while(strrchr(line,'\n') == NULL)
{
max_line_len *= 2;
line = (char *) realloc(line, max_line_len);
len = (int) strlen(line);
if(fgets(line+len,max_line_len-len,input) == NULL)
break;
}
return line;
}
void output_target(double value)
{
if(y_scaling)
{
if(value == y_min)
value = y_lower;
else if(value == y_max)
value = y_upper;
else value = y_lower + (y_upper-y_lower) *
(value - y_min)/(y_max-y_min);
}
printf("%g ",value);
}
void output(int index, double value)
{
/* skip single-valued attribute */
if(feature_max[index] == feature_min[index])
return;
if(value == feature_min[index])
value = lower;
else if(value == feature_max[index])
value = upper;
else
value = lower + (upper-lower) *
(value-feature_min[index])/
(feature_max[index]-feature_min[index]);
if(value != 0)
{
printf("%d:%g ",index, value);
new_num_nonzeros++;
}
}