asked on

file processing

i have stock.dat file ( two columns of stocks) and i created the program to read from this file and display two columns of stocks, but i cant figure out how to get the average of each stocks. actually i have two arrays of stocks with size 20, but when i try to create a function to compute the average i get incorrect answer. i would be gratitude if you help me with this problem

rmichels

Can you post your source code for your average function?

scrapdog

total=0;
for (j=0; j<20; j++) total += stock[j];
avg=stock/20;

scrapdog

i mean avg=total/20;

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rbr

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elina

ASKER

thanks for all replies. here is the original code. Average ()doesnt work correctly.
thanks a lot
Elina

#include <stdio.h>
#define SIZE 20

void Average(char [], int);

main()
{
      int i;
      char stock1[SIZE];
      char stock2[SIZE];
      FILE *cfPtr;

      if ((cfPtr = fopen ("STOCK.DAT","r")) == NULL)
            printf("file couldnt be opened\n");

      else {
            printf("%s%\t\t%s\n", "stock 1", "stock 2");
            fscanf(cfPtr, "%s%s", stock1, stock2);

            while (!feof (cfPtr)) {
                  printf("%s\t\t%s\n", stock1, stock2);
                  fscanf(cfPtr, "%s%s", stock1, stock2);
            }

      }

      Average (stock1, SIZE );

            fclose (cfPtr);

            return 0;
}

      void Average(char b[], int size)
{
      int j, temp;
      int total;
      for (j = 0; j <= size; j++)
      temp += b[j];
      total = temp / 20;
      printf("total %d\t\n", b[j]);

}

scrapdog

void Average(char b[], int size)
{
int j, temp;
int total;
for (j = 0; j <= size; j++)
temp += b[j];
total = temp / 20;
printf("total %d\t\n", total) //this line changed!!!
}

In the printf statement you were printing the last element of the array (in b[j]) instead of the average (in total).

elina

ASKER

the average is still incorrect and i cant figure out why. i got big numbers like 3456789

scrapdog

Initialize temp and total to 0.

int temp=0,
int total=0

scrapdog

Also change temp=temp/20 to temp=temp/size

This will accomplish the same thing, but will allow the average function to accept arrays other than a size of 20.

scrapdog

If rbr's answer didn't work why did you accept it?

ozo

What are you reading into stock1?
It looks like it's the characters from your last read of cfPtr

elina

ASKER

thanks guys but it still doesnt work.
for ozo: i am reading from stock1 and trying to get average
for scrapdog: about answer. i didnt pay attention that i checked it. i am new here.

scrapdog

Please repost your revised source code.

elina

ASKER

#include <stdio.h>
#define SIZE 20

void Average(float []);

main()
{
      int i;
      float stock1[SIZE];
      float stock2[SIZE];
      FILE *cfPtr;

      if ((cfPtr = fopen ("stock.dat","r")) == NULL)
            printf("file couldnt be opened\n");

      else {
            printf("%s\t%s\n", "stock 1", "stock2");
            fscanf(cfPtr, "%s\t%s", stock1, stock2);

            while (!feof (cfPtr)) {

                  printf("%s\t%s\n", stock1, stock2);
                  fscanf(cfPtr, "%s\t%s", stock1,stock2);
            }
      }
      Average (stock1);
            fclose (cfPtr);

            return 0;
}
      void Average(float b[])
{
      int j;
      float temp, total = 0;
      for (j = 0; j <= SIZE; j++)
      temp = b[j] + total;
      total = temp / SIZE; // i get '0' here
      printf("total %d\t\n", total);

}

ozo

That's a little better, but you're still only reading into stock1[0] and stock2[0], whereas you try to average from 21 elements
(even though they are only declared to contain 20 elements)

also, you're telling fscanf that stock1 and stock2 are character pointers, when they are actualy arrays of float

for( i=0; i<SIZE; i++ ){ stock1[i]=0; stock2[j]=0; }
if ((cfPtr = fopen ("stock.dat","r")) == NULL)
printf("file couldnt be opened\n");

else {
i = 0;
while ( i < SIZE && !feof (cfPtr)) {
fscanf(cfPtr, "%f\t%f", &stock1[i],&stock2[i]);
printf("%f\t%f\n", stock1[i], stock2[i]);
i++;
}
}
Average (stock1);
fclose (cfPtr);

return 0;
}
void Average(float b[])
{
int j;
float temp, total = 0;
for (j = 0; j < SIZE; j++)
total = b[j] + total;
total = total / SIZE; /*// i get '0' here */
printf("total %f\t\n", total);

elina

ASKER

after small changes it works perfectly
thanks a lot
elina

#include <stdio.h>
#define SIZE 20

void Average(float []);

main()
{
      int i;
      float stock1[SIZE];
      float stock2[SIZE];
      FILE *cfPtr;

if ((cfPtr = fopen ("stock.dat","r")) == NULL)
printf("file couldnt be opened\n");

else {
       printf("%s\t%s\n", "stock 1", "stock2");
            fscanf(cfPtr, "%f\t%f", stock1, stock2);
i = 0;
while ( i < SIZE && !feof (cfPtr)) {
            fscanf(cfPtr, "%f\t%f", &stock1[i],&stock2[i]);
            printf("%.2f\t%.2f\n", stock1[i], stock2[i]);
            i++;
            }
}
Average (stock1);
fclose (cfPtr);

return 0;
}
void Average(float b[])
{
int j;
float total = 0;
       for (j = 0; j < SIZE; j++)
            total += b[j];
            total = total / SIZE;
            printf("total %.2f\t\n", total);
       }