Bat Stats

(Latest Revision: 05/05/2001)

SIXTH CS 1500 SOLO PROGRAM: Batting Statistics

OBJECTIVE: The purpose of this programming assignment is to get practice using files, arrays, and for-loops.

THE ASSIGNMENT:

Write a program that computes batting averages.

INPUT:

You must write the program with certain facts, assumptions, and preconditions in mind:

The program gets all its input from a file named teamData.
Generally, there is no way to know exactly what will be in the file teamData when the program executes.
However we do have the assumption and precondition that teamData consists of a series of zero or more player game records like this one:
```
15 3 1 6 
```
In other words teamData consists of a series of zero or more lines of the form:
```
playerNumber hits walks outs
```
where hits, walks, and outs are non-negative integers, and playerNumber is a non-negative integer less than 25.
When the program runs, the file teamData could be any file that conforms to the rule above.
Your program must correctly process the contents of teamData, whatever its contents turn out to be.
When I test your program, some of the versions of teamData that I test it on will be files I have never shown to you. If your program works incorrectly on any of my versions of teamData, you will lose substantial credit.

You will need to use an editor to make one or more versions of teamData for your testing.

Your program will open teamData with this statement:

ifstream infile("teamData") ;

As stated above, there will be one player game record per line in teamData. The meaning of this player game record:

15 3 1 6

is that, in one particular game played by "our team," player number 15 got 3 hits, 1 walk, and 6 outs.

Consider this example of what might be part or all of the contents of teamData:


 3  1  2  3
12  2  0  4
 7  1  1  3
12  1  1  2
 7  4  1  1
12  3  1  2

This data tells us that player #3 got 1 hit, 2 walks, and 3 outs in a game. Player #12 got 2 hits, no walks, and 4 outs in one game, and in two other games player #12 got a total of 4 more hits, 2 more walks, and 4 more outs. Also player #7 got a total of 5 hits, 2 walks, and 4 outs in two games.

There are 25 players, numbered from 0 to 24. As is the case above for player #3, teamData may contain just one player game record for a particular player. As is the case for players #12 and #7 above, teamData may contain more than one player game record for a particular player. It is also possible that teamData contains no records at all for some of the players. There is nothing in the data above corresponding to most of the players. For example, there are no records corresponding to player #1.

Here is another small example of what might be part or all of the contents of teamData:


 3  1  2  3
12  2  0  4
 7  1  1  3
 8  2  2  4
24  4  2  1
 9  2  1  6
16  3  0  1
12  1  1  2
 1  3  0  9
 7  4  1  1
20  6  3 23
12  3  1  2
 4  2  1  4

OUTPUT:

The program computes a total number of hits, walks, and outs for each of the players (player #0 through player #24.) It is important to understand that sometimes the program has to add numbers from two, three, or more records in order to get the totals. There is no way to know ahead of time how many records happen to be in teamData for each player. Also, if no records occur in teamData for some player, then the program has to get all zeros for the totals of that player.

Totals are computed as sums taken over all the records corresponding to the player. For example, for player #7 in the last sample above, the total number of hits is 5=1+4, the total number of walks is 2=1+1, and the total number of outs is 4=3+1. For player #12, the totals are 6, 2, and 8.

The program also computes the batting average of each player using the following formula:

batting_average = 1000 * total_hits / (total_hits + total_outs)

The number of walks is not used in the formula for computing the batting average.

The program must print a tabular report on all the players, like this sample output:


              Batting Statistics

      Player #   Batting Av       Walks

         0             0            0
         1           250            0
         2             0            0
         3           250            2
         4           333            1
         5             0            0
         6             0            0
         7           556            2
         8           333            2
         9           250            1
        10             0            0
        11             0            0
        12           429            2
        13             0            0
        14             0            0
        15             0            0
        16           750            0
        17             0            0
        18             0            0
        19             0            0
        20           207            3
        21             0            0
        22             0            0
        23             0            0
        24           800            2

You can tell from the sample output that

This sample output corresponds to the last sample input given above.
The batting average is expressed as an integer between 0 and 1000. It does not contain a decimal point.
a player with no hits or outs is assigned a batting average of zero.

The output of your program must follow these same rules.

The tabular report that your program prints out must have a nice neat heading. The heading must include a centered title of the table, and centered titles of each of the columns of the table. Do a nice neat job. You can do it just like the sample output above if you wish.

THE DESIGN OF THE PROGRAM:

There must be at least two functions besides main in the program, each having one or more parameters. You may find you will get a better design if you use more than two functions.

You must create your own design of this program. I am expecting you to employ good principles of top-down design. Substantial credit will be withheld if you do not create a program that uses functions appropriately.

Some particulars:

Make sure that each function does one thing well.
Put no more than one return statement in any function.
Use exit() statements sparingly -- no more than one in each function.

I want you to get the experience of writing a program that uses arrays. Therefore I am requiring that your program use arrays to store counts of hits, walks, and outs. Use three arrays of 25 integers. The indices will run from 0 through 24, which is exactly the set of player numbers. Name the arrays hits, walks, and outs.

Because I am going to test all the programs by compiling and running them on different versions of the input file, I need everyone in the class to use exactly the same name for the input file. Therefore, please name your file teamData and use the command:

ifstream infile("teamData") ;

in your program.

To see some C++ code with similarities to the code you need to write, look at the sample program that reads and prints golf scores. Also check out the sample input and corresponding output for the golf scores problem.

Note: Come to class to get more discussion of how to design a solution to this problem.

FORM AND FORMATTING REQUIREMENTS:

Write appropriate header comments for each of your functions. Header comments are the comments that appear at the beginning of the function, telling what it's purpose is and what the preconditions and postconditions are, and so forth. You may pattern your header comments after the example code in your text book, or you may use this information as your guide.

At the beginning of your program file put a header comment like this:


  /* PROGRAM Batting Statistics */

  /*

  Name:          Gordon Goodguy
  User Name:     goodge
  Course:        CS 1500, Computer Programming I
  Instructor:    John Sarraille
  Date:          November 31, 2001

  */

Of course, in place of "Gordon Goodguy," you must put your own full name. In place of "goodge" put your user (login) name. In place of "November 31, 2001" put the date that you finished the program. Note that the comment delimiters /* and */ are important. They need to be placed correctly or you will get compiler errors.

TESTING:

Since the specifications allow the file teamData to be empty, you will need to make at least two versions of teamData for testing.

Here's a nice way of managing different versions of teamData for testing:

Make an empty file and call it teamData01. (The command
```
 cat /dev/null > teamData01 
```
makes an empty file called teamData01.)
Make an "average" version of a teamData file and call it teamData02.
When you want to run the program with teamData01 as the input, just do the command
```
cp teamData01 teamData 
```
first.
Similarly, when you want to run the program with teamData02 as the input, just do the command
```
cp teamData02 teamData
```
first.

WHAT TO TURN IN:

Before midnight on the due date, e-mail the following two items to me:

A copy of the source code, properly documented.
A filtered script showing an appropriate number of test runs with appropriate inputs.

My e-mail address is: john@ishi.csustan.edu

Please use the following subject lines exactly for the e-mails:

For the source file: CS1500_Solo6_Source

and for the script file: CS1500_Solo6_Script.

Note that there are no spaces in these subject lines. If you like, you can copy and paste the subject lines right from this document.

Thanks! Your use of these subject lines will really be a big help to me when I try to sort through the perhaps hundred e-mail messages that will be in my electronic mailbox!

WHEN IS THIS ASSIGNMENT DUE?

Look for the due date in the class schedule. (It's at the top level of the class directory.)