Thread: im printing 3 lines of the same on all my lines, please help

Code:

/* Preprocessor directives */
#include <stdio.h>
#include <math.h>
#define input_file "c:\\engr 200\\train.txt"
#define output_file "c:\\engr 200\\train_report.txt"


/* Define the structure to represent a tsunami */
struct trains
{
   double time, displace, velocity;
};
/* Main Function */
int main(void)
{
   /* Declare and initialize variables */
   struct trains tr[51];
   int nrows,ncols, i, j;
   double displace, velocity, time;
   FILE *train, *train_report;


   /* Open input file */
   train = fopen(input_file,"r");
   train_report = fopen(output_file,"w");
   
   /* Verify input file, read control number, and hurricane data */
   if(train == NULL)
   {
      printf("\n\n\n\n   ERROR OPENING INPUT FILE.");
      printf("\n\n   PROGRAM TERMINATED.\n\n\n");
      return 0;
   }
   else
   {
      /* Read control number */
      fscanf(train,"%i %i",&nrows,&ncols);
      
      /* Read train data into array */
      for(j=0; j<=ncols-1; j++)
      {
        for(i=0; i<=nrows-1; i++)
            {
            fscanf(train,"%lf %lf %lf",&tr[i].time, &tr[i].displace,
             &tr[i].velocity);
            }
      }
   }


   /* calculations */
      for(i=0; i<=nrows-1; i++)
      {
         for(j=0; j<=ncols-1; j++)
            {
               tr[i].displace = 4.219*(exp(-1.58*time)-exp(-6.32*time));
               tr[i].velocity = 26.67*exp(-6.32*time)-6.67*exp(-1.58*time);
            }
       }
  
      /* Print headings */
   printf("************ START REPORT ***********"
          "\n\n     TRAIN CAR STOPPING ANALYSIS"
          "\n\n\n  Time      Displacement     Velocity"
          "\n   (s)           (m)           (m/s)");
   fprintf(train_report,"************ START REPORT ***********"
          "\n\n     TRAIN CAR STOPPING ANALYSIS"
          "\n\n\n  Time      Displacement     Velocity"
          "\n   (s)           (m)           (m/s)");
      
   /* Print array */
   for(i=0; i<=nrows-1; i++)
      for(j=0; j<=ncols-1; j++)
      {
      printf("\n%6.3f         %6.3f         %6.3f",tr[i].time,
             tr[i].displace,tr[i].velocity);
      fprintf(train_report,"\n%6.3f         %6.3f         %6.3f",tr[i].time,
             tr[i].displace,tr[i].velocity);         
      }
   
   /* Print end */
   printf("\n\n************ END REPORT *************\n\n\n");
   fprintf(train_report,"\n\n************ END REPORT *************\n\n\n");
   
   /* Close the input file */
   fclose(train);
   fclose(train_report);


   /* Exit the program */
   return 0;
}
/******************************************************************************/

You should be getting a couple of warnings about this code that need to be fixed:

||=== Build: Debug in c_homework (compiler: GNU GCC Compiler) ===|
main.c||In function ‘main’:|
main.c|19|warning: unused variable ‘velocity’ [-Wunused-variable]|
main.c|19|warning: unused variable ‘displace’ [-Wunused-variable]|
main.c|56|warning: ‘time’ may be used uninitialized in this function [-Wmaybe-uninitialized]|
||=== Build finished: 0 error(s), 3 warning(s) (0 minute(s), 0 second(s)) ===|

Jim

I think i fixed the warnings, but i am still printing 3 lines of the same of every line. I am using the dev c compiler if that helps. BTW thanks for your help.

Code:

/* Preprocessor directives */
#include <stdio.h>
#include <math.h>
#define input_file "c:\\engr 200\\train.txt"
#define output_file "c:\\engr 200\\train_report.txt"


/* Define the structure to represent a tsunami */
struct trains
{
   double time, displace, velocity;
};
/* Main Function */
int main(void)
{
   /* Declare and initialize variables */
   struct trains tr[51];
   int nrows,ncols, i, j;
   FILE *train, *train_report;


   /* Open input file */
   train = fopen(input_file,"r");
   train_report = fopen(output_file,"w");
   
   /* Verify input file, read control number, and hurricane data */
   if(train == NULL)
   {
      printf("\n\n\n\n   ERROR OPENING INPUT FILE.");
      printf("\n\n   PROGRAM TERMINATED.\n\n\n");
      return 0;
   }
   else
   {
      /* Read control number */
      fscanf(train,"%i %i",&nrows,&ncols);
      
      /* Read train data into array */
      for(j=0; j<=ncols-1; j++)
      {
        for(i=0; i<=nrows-1; i++)
            {
			fscanf(train,"%lf %lf %lf",&tr[i].time, &tr[i].displace,
			 &tr[i].velocity);
		    }
      }
   }


   /* calculations */
      for(i=0; i<=nrows-1; i++)
      {
         for(j=0; j<=ncols-1; j++)
            {
			   tr[i].displace = 4.219*(exp(-1.58*tr[i].time)-
			        exp(-6.32*tr[i].time));
			   
               tr[i].velocity = 26.67*exp(-6.32*tr[i].time)-
			        6.67*exp(-1.58*tr[i].time);
            }
       }
  
      /* Print headings */
   printf("************ START REPORT ***********"
          "\n\n     TRAIN CAR STOPPING ANALYSIS"
		  "\n\n\n  Time      Displacement     Velocity"
		  "\n   (s)           (m)           (m/s)");
   fprintf(train_report,"************ START REPORT ***********"
          "\n\n     TRAIN CAR STOPPING ANALYSIS"
		  "\n\n\n  Time      Displacement     Velocity"
		  "\n   (s)           (m)           (m/s)");
	  
   /* Print array */
   for(i=0; i<=nrows-1; i++)
      for(j=0; j<=ncols-1; j++)
      {
      printf("\n%6.3f         %6.3f         %6.3f",tr[i].time,
	         tr[i].displace,tr[i].velocity);
	  fprintf(train_report,"\n%6.3f         %6.3f         %6.3f",tr[i].time,
	         tr[i].displace,tr[i].velocity);		 
      }
   
   /* Print end */
   printf("\n\n************ END REPORT *************\n\n\n");
   fprintf(train_report,"\n\n************ END REPORT *************\n\n\n");
   
   /* Close the input file */
   fclose(train);
   fclose(train_report);


   /* Exit the program */
   return 0;
}
/******************************************************************************/

i don't know, im just following examples that my instructor gave me, if i knew what i was doing i would't be asking for help. but i did try to remove the j and place an i in its place, that made things worse.

Originally Posted by Salem

Code:

   for(i=0; i<=nrows-1; i++)
      for(j=0; j<=ncols-1; j++)

So why do you have a j loop when you print, when j is never used in any of your print statements?

In fact, all your nested loops have one subscript unused.

i just removed the second for statement and it cleaned it up, thanks for the hint.

ok i have added the last part to my code, and that is to print "The train car stopped moving forward at x.xxx seconds and x.xxx meters."
how do I get this line to just print one time and to stop printing the rest?

Code:

/* Preprocessor directives */
#include <stdio.h>
#include <math.h>
#define input_file "c:\\engr 200\\train.txt"
#define output_file "c:\\engr 200\\train_report.txt"


/* Define the structure to represent a tsunami */
struct trains
{
   double time, displace, velocity;
};
/* Main Function */
int main(void)
{
   /* Declare and initialize variables */
   struct trains tr[51];
   int nrows,ncols, i, j;
   FILE *train, *train_report;


   /* Open input file */
   train = fopen(input_file,"r");
   train_report = fopen(output_file,"w");
   
   /* Verify input file, read control number, and hurricane data */
   if(train == NULL)
   {
      printf("\n\n\n\n   ERROR OPENING INPUT FILE.");
      printf("\n\n   PROGRAM TERMINATED.\n\n\n");
      return 0;
   }
   else
   {
      /* Read control number */
      fscanf(train,"%i %i",&nrows,&ncols);
      
      /* Read train data into array */
      for(j=0; j<=ncols-1; j++)
      {
        for(i=0; i<=nrows-1; i++)
            {
			fscanf(train,"%lf %lf %lf",&tr[i].time, &tr[i].displace,
			 &tr[i].velocity);
		    }
      }
   }


   /* calculations */
      for(i=0; i<=nrows-1; i++)
      {
         for(j=0; j<=ncols-1; j++)
            {
			   tr[i].displace = 4.219*(exp(-1.58*tr[i].time)-
			        exp(-6.32*tr[i].time));
			   
               tr[i].velocity = 26.67*exp(-6.32*tr[i].time)-
			        6.67*exp(-1.58*tr[i].time);
            }
       }
  
      /* Print headings */
   printf("************ START REPORT ***********"
          "\n\n     TRAIN CAR STOPPING ANALYSIS"
		  "\n\n\n  Time      Displacement     Velocity"
		  "\n   (s)           (m)           (m/s)");
   fprintf(train_report,"************ START REPORT ***********"
          "\n\n     TRAIN CAR STOPPING ANALYSIS"
		  "\n\n\n  Time      Displacement     Velocity"
		  "\n   (s)           (m)           (m/s)");
	  
   /* Print array */
   for(i=0; i<=nrows-1; i++)
      {
      if(tr[i].velocity<0)
	    {printf("\nThe train car stopped moving forward at %6.3f seconds and"
		       " %6.3f meters.",tr[i].time,tr[i].displace);	
	    }
	else
	{  
      printf("\n%6.3f         %6.3f         %6.3f",tr[i].time,
	         tr[i].displace,tr[i].velocity);
	  fprintf(train_report,"\n%6.3f         %6.3f         %6.3f",tr[i].time,
	         tr[i].displace,tr[i].velocity);
    }
      }
   
   /* Print end */
   printf("\n\n************ END REPORT *************\n\n\n");
   fprintf(train_report,"\n\n************ END REPORT *************\n\n\n");
   
   /* Close the input file */
   fclose(train);
   fclose(train_report);


   /* Exit the program */
   return 0;
}
/******************************************************************************/

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