asked on

can any body help!!!!I have bleaque knowledge of C++ ...

I require this array to output the average number ..... form a given set of numbers
heres the code which just displays without the average

#include "fstream.h"
#include <string.h>
#include<stdio.h>

int main()
{
char filenameh[64];
int i=0;
char newfilename[128];
ifstream ifshl; ifshl.open("datafiles.lis");
float x[1056]; float y[1056];

while(!ifshl.eof())
{
      ifshl>>filenameh;


      strcpy(newfilename,filenameh);
      strcat(newfilename,".new");

      ifstream ifsh(filenameh);
      if(ifsh.bad())
      printf("Error Opening %s\n",filenameh);

      ofstream ofs(newfilename);
      if(ofs.bad())
      printf("Error opening %s\n",newfilename);

for (int i=0; i<1056; i++)
      {
ifsh>>y[i] >> x[i];


      ofs << x[i] << endl;
      }

ifsh.close();
ofs.close();
}
ifshl.close();
return 0;
}

this is what i require :-
"I've got an array of number that I want to add
so ive got x[i] where i is 1 to 1056
so x is a different value for each value of i
need to work out the average of the numbers"

ASKER CERTIFIED SOLUTION

andrewjb

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Avik Dasgupta

why r u openning and closing files several times. If u have line by line numbers, performing this may do

#include<fstream.h>

void main()
{
ifstream fl1("datafiles.lis",ios::in);
// check for file existance
ofstream fl2("datafiles.new",ios::out);
int x[1056],count=0,sum=0,avg,i=0;
while(fl1>>x[i]){ // i don't understand the role of y[i]
count++;
sum=sum+x[i]; // cumulate sum
cout << x[i] << endl;
}
avg=sum/count; // compute average
cout<<avg<<endl;
fl1.close();
fl2.close();
}

Hope this works fine !

Avik.

Ikram_Bohra

ASKER

@andrewJB-----

sorry for being a nuisance as i am not very familiar with C++ at all its just that i require is just part of a module at University.

hers the error i get
--------------------Configuration: change2 - Win32 Debug--------------------
Compiling...
change2.cpp
C:\Documents and Settings\rdudhwal\Desktop\change2.cpp(42) : warning C4244: 'initializing' : conversion from 'double' to 'float', possible loss of data

change2.obj - 0 error(s), 1 warning(s)

.........when i compile this

#include "fstream.h"
#include <string.h>
#include<stdio.h>

int main()
{
char filenameh[64];
int i=0;
char newfilename[128];
ifstream ifshl; ifshl.open("datafiles.lis");
float x[1056]; float y[1056];

while(!ifshl.eof())
{
      ifshl>>filenameh;


      strcpy(newfilename,filenameh);
      strcat(newfilename,".new");

      ifstream ifsh(filenameh);
      if(ifsh.bad())
      printf("Error Opening %s\n",filenameh);

      ofstream ofs(newfilename);
      if(ofs.bad())
      printf("Error opening %s\n",newfilename);

      float lSum = 0;

      for (int i=0; i<1056; i++)
      {
            ifsh>>y[i] >> x[i];


            ofs << x[i] << endl;
            lSum += x[i];
      }

      float lAverage = lSum / 1056.0;

      ifsh.close();
      ofs.close();
      }
      ifshl.close();
       return 0;
      }

andrewjb

It's only a warning. I think because 1056.0 is considered a double, not a float.

So, it doesn't really matter in this case, but
float lAverage = lSum / (float)1056.0;
would sort it.

Ikram_Bohra

ASKER

@andrewJB-----

thank the problem has now been sorted so u can ignore the last post

thank you