calculate average from a file

same program as before. reads in a text file. in the text file there are males and females and scores for them.
I would like to calculate the average for all the scores for the males or females.
what would be the best way to go about this?
I am sure i would have to first find all the females and then add the scores up and didvide by the number of females. but not sure how to go about that?

Code:

#include "stdafx.h"
#include <iostream>
#include <fstream>
#include <string>
#include <iomanip>

using namespace std;

int _tmain(int argc, _TCHAR* argv[])
{

char name[25];
char gender;
char code[5];
int score;
int count = 0;

char reply;
ifstream infile;
string myfile;

//char process[200];

ifstream inputFile;

cout << "Enter file name with the extension(Example: scores.txt): " << endl;

cin >> myfile;

inputFile.open (myfile.c_str(), ios::in);

if(!inputFile)
 {
  cerr << "Can't open input file " << myfile << endl;
  cin >> reply;
  exit(1);
}



while(!inputFile.eof())
{
inputFile >> name;
count++;
cout << name;
inputFile >> gender;
cout << gender;
inputFile >> code;
cout << code;
inputFile >> score;
cout << score << endl;

//inputFile.getline(process,200);

}


 }
 

 cin >> reply;
  return 0;
}

output:
M = male
F= female
CC = comunity college.
just to clarify

Code:

Enter file name with the extension(Example: scores.txt):
scores.txt
Bailey    M CC  68
Harrison    F CC  71
Grant    M UN  75
Peterson    F UN  69
Hsu    M UN  79
Bowles    M CC  75
Anderson    F UN  64
Nguyen    F CC  68
Sharp    F CC  75
Jones    M UN  75
McMillan    F UN  80
Gabriel    F UN  62
    F     62

not sure why it's picking up the last F 62 thats from the last name Gabriel.

thank you!

No need to read everything into memory.

Keep 4 variables - num_females, num_males, sum_males, sum_females.

Read the file. For every entry, add the score to either sum_females or sum_males, and increment num_females or num_males.

Then, avg is just "sum / num".

Oh and, indent properly.

Originally Posted by mrsirpoopsalot

not sure why it's picking up the last F 62 thats from the last name Gabriel.

thank you!

And this is why you don't use .eof() to control a loop.

I am getting the same results when i do this :

Code:

while(inputFile)
{
inputFile >> name;
cout << name;
inputFile >> gender;
cout << setw(5) << gender;
inputFile >> code;
cout << setw(3) << code;
inputFile >> score;
cout << setw(4) << score << endl;

//inputFile.getline(process,200);

}

output:

Code:

Enter file name with the extension(Example: scores.txt):
scores.txt
Bailey    M CC  68
Harrison    F CC  71
Grant    M UN  75
Peterson    F UN  69
Hsu    M UN  79
Bowles    M CC  75
Anderson    F UN  64
Nguyen    F CC  68
Sharp    F CC  75
Jones    M UN  75
McMillan    F UN  80
Gabriel    F UN  62
    F     62

that last F 62 should not be there..

What is your current code? Also, what is the sample input?

my current code:
I will fix the identing later.

Code:

#include "stdafx.h"
#include <iostream>
#include <fstream>
#include <string>
#include <iomanip>

using namespace std;

int _tmain(int argc, _TCHAR* argv[])
{
int num_females = 0;
int num_males = 0; 
int sum_males; 
int sum_females;

char name[25];
char gender;
char code[5];
int score;
int count = 0;

char reply;
ifstream infile;
string myfile;

//char process[200];

ifstream inputFile;

cout << "Enter file name with the extension(Example: scores.txt): " << endl;

cin >> myfile;

inputFile.open (myfile.c_str(), ios::in);

if(!inputFile)
 {
  cerr << "Can't open input file " << myfile << endl;
  cin >> reply;
  exit(1);
}



while(inputFile)
{
inputFile >> name;
cout << name;
inputFile >> gender;
if(gender == 'F')
{
	num_females++;
}
else
{
	num_males++;
}
cout << setw(5) << gender;
inputFile >> code;
cout << setw(3) << code;
inputFile >> score;
cout << setw(4) << score << endl;

//inputFile.getline(process,200);

}


 cout << "number of males = " << num_males;
 

 cin >> reply;
  return 0;
}

output:

Code:

Enter file name with the extension(Example: scores.txt):
scores.txt
Bailey    M CC  68
Harrison    F CC  71
Grant    M UN  75
Peterson    F UN  69
Hsu    M UN  79
Bowles    M CC  75
Anderson    F UN  64
Nguyen    F CC  68
Sharp    F CC  75
Jones    M UN  75
McMillan    F UN  80
Gabriel    F UN  62
    F     62
number of males = 5

that last F 62 is part of Gabriel and should not be there..
here is a copy of scores.txt

Code:

Bailey           M CC 68
Harrison         F CC 71
Grant            M UN 75
Peterson         F UN 69
Hsu              M UN 79
Bowles           M CC 75
Anderson         F UN 64
Nguyen           F CC 68
Sharp            F CC 75
Jones            M UN 75
McMillan         F UN 80
Gabriel          F UN 62

Originally Posted by mrsirpoopsalot

I will fix the identing later.

You could indent while you code. If you want such a lazy approach to indentation, use a source code formatting tool (your text editor/IDE may even come with one, and it probably can also be configured to help you indent while you code).

Originally Posted by mrsirpoopsalot

that last F 62 is part of Gabriel and should not be there..
here is a copy of scores.txt

I am unable to duplicate your output. However, I do get an output with this line repeated:

Code:

Gabriel    F UN  62

The reason is as before: you need to control the loop with the return value of the functions used to read. In this case you could write:

Code:

while (inputFile >> name >> gender)
{
    cout << name;
    if (gender == 'F')
    {
        num_females++;
    }
    else
    {
        num_males++;
    }
    cout << setw(5) << gender;
    inputFile >> code;
    cout << setw(3) << code;
    inputFile >> score;
    cout << setw(4) << score << endl;
}

well if i do something like this

Code:

while(inputFile >> name )
{
inputFile >> name;
cout << name;
inputFile >> gender;
if(gender == 'F')
{
	num_females++;
}
else
{
	num_males++;
}
cout << setw(5) << gender;
inputFile >> code;
cout << setw(3) << code;
inputFile >> score;
cout << setw(4) << score << endl;

it wont display the name.. or if i add more to the loop condition it wont display those results.

Originally Posted by mrsirpoopsalot

well if i do something like this

Compare your code and mine. The critical difference is that you read into name twice on each iteration.

laserlight,

thank you it works, but im a little confused by what the condition is.
why cant we just use name and why name and gender?

Originally Posted by mrsirpoopsalot

thank you it works, but im a little confused by what the condition is.

The underlying problem is that the EOF condition is only set when an attempt is made to read, and finds that it has reached the end of the file. This is why your original loop runs one extra time: the condition is tested and found that the EOF bit is not set, but actually the file has been completely read.

Originally Posted by mrsirpoopsalot

why cant we just use name and why name and gender?

To avoid the problem that you faced originally, it is enough to just read into name in the loop condition. The advantage of including gender, and even including code and score, is that the loop will terminate if there is invalid input, or if the last line is incomplete.

thank you