| @@ -0,0 +1,212 @@ | |||
| #include <stdio.h> | |||
| #include <string.h> | |||
| #include <stdlib.h> | |||
| #include <ctype.h> | |||
| #include <errno.h> | |||
| #include "mex.h" | |||
| #ifdef MX_API_VER | |||
| #if MX_API_VER < 0x07030000 | |||
| typedef int mwIndex; | |||
| #endif | |||
| #endif | |||
| #ifndef max | |||
| #define max(x,y) (((x)>(y))?(x):(y)) | |||
| #endif | |||
| #ifndef min | |||
| #define min(x,y) (((x)<(y))?(x):(y)) | |||
| #endif | |||
| void exit_with_help() | |||
| { | |||
| mexPrintf( | |||
| "Usage: [label_vector, instance_matrix] = libsvmread('filename');\n" | |||
| ); | |||
| } | |||
| static void fake_answer(int nlhs, mxArray *plhs[]) | |||
| { | |||
| int i; | |||
| for(i=0;i<nlhs;i++) | |||
| plhs[i] = mxCreateDoubleMatrix(0, 0, mxREAL); | |||
| } | |||
| static char *line; | |||
| static int max_line_len; | |||
| static 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; | |||
| } | |||
| // read in a problem (in libsvm format) | |||
| void read_problem(const char *filename, int nlhs, mxArray *plhs[]) | |||
| { | |||
| int max_index, min_index, inst_max_index; | |||
| size_t elements, k, i, l=0; | |||
| FILE *fp = fopen(filename,"r"); | |||
| char *endptr; | |||
| mwIndex *ir, *jc; | |||
| double *labels, *samples; | |||
| if(fp == NULL) | |||
| { | |||
| mexPrintf("can't open input file %s\n",filename); | |||
| fake_answer(nlhs, plhs); | |||
| return; | |||
| } | |||
| max_line_len = 1024; | |||
| line = (char *) malloc(max_line_len*sizeof(char)); | |||
| max_index = 0; | |||
| min_index = 1; // our index starts from 1 | |||
| elements = 0; | |||
| while(readline(fp) != NULL) | |||
| { | |||
| char *idx, *val; | |||
| // features | |||
| int index = 0; | |||
| inst_max_index = -1; // strtol gives 0 if wrong format, and precomputed kernel has <index> start from 0 | |||
| strtok(line," \t"); // label | |||
| while (1) | |||
| { | |||
| idx = strtok(NULL,":"); // index:value | |||
| val = strtok(NULL," \t"); | |||
| if(val == NULL) | |||
| break; | |||
| errno = 0; | |||
| index = (int) strtol(idx,&endptr,10); | |||
| if(endptr == idx || errno != 0 || *endptr != '\0' || index <= inst_max_index) | |||
| { | |||
| mexPrintf("Wrong input format at line %d\n",l+1); | |||
| fake_answer(nlhs, plhs); | |||
| return; | |||
| } | |||
| else | |||
| inst_max_index = index; | |||
| min_index = min(min_index, index); | |||
| elements++; | |||
| } | |||
| max_index = max(max_index, inst_max_index); | |||
| l++; | |||
| } | |||
| rewind(fp); | |||
| // y | |||
| plhs[0] = mxCreateDoubleMatrix(l, 1, mxREAL); | |||
| // x^T | |||
| if (min_index <= 0) | |||
| plhs[1] = mxCreateSparse(max_index-min_index+1, l, elements, mxREAL); | |||
| else | |||
| plhs[1] = mxCreateSparse(max_index, l, elements, mxREAL); | |||
| labels = mxGetPr(plhs[0]); | |||
| samples = mxGetPr(plhs[1]); | |||
| ir = mxGetIr(plhs[1]); | |||
| jc = mxGetJc(plhs[1]); | |||
| k=0; | |||
| for(i=0;i<l;i++) | |||
| { | |||
| char *idx, *val, *label; | |||
| jc[i] = k; | |||
| readline(fp); | |||
| label = strtok(line," \t\n"); | |||
| if(label == NULL) | |||
| { | |||
| mexPrintf("Empty line at line %d\n",i+1); | |||
| fake_answer(nlhs, plhs); | |||
| return; | |||
| } | |||
| labels[i] = strtod(label,&endptr); | |||
| if(endptr == label || *endptr != '\0') | |||
| { | |||
| mexPrintf("Wrong input format at line %d\n",i+1); | |||
| fake_answer(nlhs, plhs); | |||
| return; | |||
| } | |||
| // features | |||
| while(1) | |||
| { | |||
| idx = strtok(NULL,":"); | |||
| val = strtok(NULL," \t"); | |||
| if(val == NULL) | |||
| break; | |||
| ir[k] = (mwIndex) (strtol(idx,&endptr,10) - min_index); // precomputed kernel has <index> start from 0 | |||
| errno = 0; | |||
| samples[k] = strtod(val,&endptr); | |||
| if (endptr == val || errno != 0 || (*endptr != '\0' && !isspace(*endptr))) | |||
| { | |||
| mexPrintf("Wrong input format at line %d\n",i+1); | |||
| fake_answer(nlhs, plhs); | |||
| return; | |||
| } | |||
| ++k; | |||
| } | |||
| } | |||
| jc[l] = k; | |||
| fclose(fp); | |||
| free(line); | |||
| { | |||
| mxArray *rhs[1], *lhs[1]; | |||
| rhs[0] = plhs[1]; | |||
| if(mexCallMATLAB(1, lhs, 1, rhs, "transpose")) | |||
| { | |||
| mexPrintf("Error: cannot transpose problem\n"); | |||
| fake_answer(nlhs, plhs); | |||
| return; | |||
| } | |||
| plhs[1] = lhs[0]; | |||
| } | |||
| } | |||
| void mexFunction( int nlhs, mxArray *plhs[], | |||
| int nrhs, const mxArray *prhs[] ) | |||
| { | |||
| char filename[256]; | |||
| if(nrhs != 1 || nlhs != 2) | |||
| { | |||
| exit_with_help(); | |||
| fake_answer(nlhs, plhs); | |||
| return; | |||
| } | |||
| mxGetString(prhs[0], filename, mxGetN(prhs[0]) + 1); | |||
| if(filename == NULL) | |||
| { | |||
| mexPrintf("Error: filename is NULL\n"); | |||
| return; | |||
| } | |||
| read_problem(filename, nlhs, plhs); | |||
| return; | |||
| } | |||