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Reading  a large number of floating point data into a dynamically allocated 2 dimensional variable

Posted on 2001-06-24
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Last Modified: 2010-04-02
I wrote a very very simple program to write 40000*84 floating point data into a file and then try to retrieve it back into a 2 dimensional dynamically allocated variable.

#include <stdlib.h>
#include <stdio.h>
#define TOTAL_TRAIN     40000
#define TOTAL_FEATURE     84

void main()
{
     FILE* ftest;
     ftest=fopen  
        ("C:\\windows\\desktop\\train.txt","w");
     if(ftest==NULL)     exit(0);
     
     float num=0.0;
     for(long i=0; i<(TOTAL_TRAIN*TOTAL_FEATURE); i++)
     {
          num=num+1.2;
          fprintf(ftest,"%f\n",num);
     }
     fclose(ftest);
     printf("file write done");
     
     FILE* fsort;
     long total=TOTAL_TRAIN;
     fsort=fopen
        ("C:\\windows\\desktop\\train.txt","r");
     if(fsort==NULL)     exit(0);
     
     float** features=new float* [TOTAL_TRAIN];
     for(i=0; i<TOTAL_TRAIN; i++)
          features[i]=new float [TOTAL_FEATURE];
     
     for(i=0; i<TOTAL_TRAIN; i++)
     {
          printf("%d\n",i);
          for(int j=0; j<TOTAL_FEATURE; j++)
          {              
          fscanf(fsort,"%f",&features[j][i]);
          }
     }
     
     fclose(fsort);

     printf("All features had been loaded\n");
       
        for(i=0; i<TOTAL_TRAIN; i++)
     delete [] features[i];
     delete[] features;
}
 
Writing into a file is not a problem but when I try to retrieve it back only 750*84 out of 40000*84 samples can be retrieved.
Try to run this program. If any one can find any solution can you inform me as soon as possible.

Is it due to memory problem. 40000*84*4(float point data size is 4bytes)=13.44Mbyte. I have a 64Mbyte of SDRAM, Pentium 3 600Mhz and 14Gbyte of HDD.
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Question by:tiagrajah
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3 Comments
 
LVL 3

Accepted Solution

by:
elcapitan earned 30 total points
ID: 6223509
You have access violation.
Replace the line: fscanf(fsort,"%f",&features[j][i]);
with the line: fscanf(fsort,"%f",&features[i][j]);

--EC--
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LVL 22

Expert Comment

by:nietod
ID: 6224264
alcapitan, you must have great eyes, or a much better font than I do!  :-)

Out of curiosity, was this posted as a comment or answer?
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LVL 3

Expert Comment

by:elcapitan
ID: 6224286
Thanks,
I posted it as comment

--EC--
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