Sample Documentation
Author: Glynis Hamel
Date: 3/15/96
Version: 1.0
Project ID: Documentation Sample
CS Class: CS1005
Programming Language: C
OS/Hardware dependencies: None
Problem Description: Program inputs a list of numbers, calculates
the average of the numbers, and displays those
numbers from the list that are greater than or
equal to the average.
Overall Design:
System structure N/A
Data representation Input values stored in a one-dimensional array.
All references to size of array made through
constant macro SIZE.
Algorithms Average =(sum of numbers) / (number of numbers)
For-loop steps through array to compare each
number to average.
Program Assumptions
and Restrictions: Number of values input is hard-coded.
Program does not check for overflow or
underflow, or for round-off errors.
Program does not recover from erroneous
(non-numeric) input.
Interfaces:
User User prompted for each input value separately.
File/D-B None
Program/Module N/A
Implementation Details:
Data Array that holds numbers is type float
Variables float numbers[SIZE], float average
Algorithm Sum of numbers is calculated after (rather
than within,) the input loop, to separate
the input and computation functions.
How to build the program: gcc sample.prog.c
Program Source:
#include <stdio.h>
#define SIZE 5
/* Program will input a list of numbers, calculate the average of the
numbers, and output those numbers from the list that are greater than
or equal to the average
*/
main ()
{
float numbers [SIZE]; /* array to hold list of numbers */
int i; /* index into array, loop control */
float average;
printf ("\nThis program will calculate the average of a list of numbers,\n");
printf ("then display those numbers from the list that are greater than\n");
printf ("or equal to the average.\n\n");
/* prompt for and accept list of numbers */
printf ("Enter %d numbers now:\n\n", SIZE);
for (i=0; i < SIZE; i++)
{
printf ("Enter value #%d: ", i+1);
scanf ("%f", &numbers[i]);
printf ("\n");
}
/* sum numbers, then divide by SIZE to get average */
for (i=0, average=0.0; i < SIZE; i++)
average += numbers[i];
average = average / SIZE;
printf ("\nThe average of the numbers is %f\n\n", average);
/* compare each number to the average. Print those greater
than or equal to the average
*/
printf ("These numbers are greater than or equal to the average...\n\n");
for (i=0; i < SIZE; i++)
if (numbers[i] >= average)
printf ("%f\n", numbers[i]);
printf ("\nProgram terminating...\n");
}
Additional Files: None.
Results:
Script started on Fri Mar 15 16:24:39 1996
sequoia.WPI.EDU: /users/csfaculty/ghamel/doc.standard% a.out
This program will calculate the average of a list of numbers,
then display those numbers from the list that are greater than
or equal to the average.
Enter 5 numbers now:
Enter value #1: 12.7
Enter value #2: 15
Enter value #3: 5.67
Enter value #4: 9.3
Enter value #5: 13
The average of the numbers is 11.134001
These numbers are greater than or equal to the average...
12.700000
15.000000
13.000000
Program terminating...
sequoia.WPI.EDU: /users/csfaculty/ghamel/doc.standard% exit
exit
script done on Fri Mar 15 16:24:57 1996
Test Procedures: Value of constant SIZE was changed and
program recompiled to check for errors
in usage of SIZE.
Program was run with various data sets
including all zero's, mixture of positive
and negative numbers, very large and very
small numbers.
Test Data: Data used in sample execution (above)
shows example of round-off error.
Performance Evaluation: N/A
Time/Space
User Interface
References: None.
Maintained by webmaster@cs.wpi.eduLast modified: August 15, 2006 16:35:58