//=========================================================================
#define PROGRAMMER "BAHN, William"
#define PROG_CODE  "bahw"
#define COURSE     "ECE-1021"
#define YEAR       (2003)
#define TERM       "Fall"
#define SECTION    (0)
#define ASSIGNMENT "RWA 3.5"
#define REVISION   (0)
#define TITLE      "Real World Application from Section 3.5"
#define SUBTITLE   "Statistical Measures"
#define EMAIL      "wbahn@eas.uccs.edu"
#define FILENAME   "rwa0305.c"
//=========================================================================

// PROBLEM:
//
// The enteres a string of floating point values and the following
// statistical measures are computed and displayed:
//
//   number of values
//   maximum value
//   minimum value
//   sum of all values
//   mean of all values
//   variance
//   std deviation
//
// PSEUDOCODE
// 1) GET: Value
// 2) IF: User entered EOF
// 2.1) PUT: Program Termination Message to screen.
// 2.2) EXIT program
// 3) REM: Initialize values
// 3.1) SET: NumberofValues = 1
// 3.2) SET: MinValue = Value
// 3.3) SET: MaxValue = Value
// 3.4) SET: Sum = Value
// 3.5) SET: Variance = 0
// 4) LOOP: Until the user enters ^Z.
// 4.1) SET: Increment NumberOfValues
// 4.2) SET: Sum = Sum + Value
// 4.3) IF: MinValue > Value
// 4.3.1) MinValue = Value
// 4.4) IF: MaxValue < Value
// 4.4.1) MaxValue = Value
// 4.5) SET: variance = variance + (value^2)
// 5) REM: Calculate Variance
// 5.1) SET: mean = sum / NumberOfValues
// 5.2) SET: variance = variance / NumberOfValues
// 5.3) SET: variance = variance - (mean^2)
// 6) StdDev = sqrt(variance)
// 7) PUT: All statistical measures to screen.
// 8) PUT: Program Termination Message to screen.
// 9) EXIT program

//== INCLUDE FILES ========================================================
#include <stdio.h> // printf(), scanf(), EOF
#include <math.h>  // sqrt()

//== FUNCTION PROTOTYPES ==================================================
void PrintHeader(void);

//== MAIN FUNCTION ========================================================
int main(void)
{
	int num;
	double value;
	double min, max, mean, sum, var, sdev;

	PrintHeader();
	printf("\n"); // Print a blank line

	printf("Enter Ctlr-Z to quit.\n");
	printf("\n"); // Print a blank line

	// 1) GET: Value
	// 2) IF: User entered EOF
	// 2.1) PUT: Program Termination Message to screen.
	// 2.2) EXIT program

	printf("Enter the data values: ");
	if(EOF == scanf("%lf", &value))
	{
		printf("\n"); // Carriage Return for input line after ^Z is entered.
		printf("No Data Entered - Program Terminated!\n");
		return(1);
	}

	// 3) REM: Initialize values
	// 3.1) SET: NumberofValues = 1
	// 3.2) SET: MinValue = Value
	// 3.3) SET: MaxValue = Value
	// 3.4) SET: Sum = Value
	// 3.5) SET: Variance = 0

	num = 1;
	min = value;
	max = value;
	sum = value;
	var = value * value;

	// 4) LOOP: Until the user enters ^Z.
	// 4.1) SET: Increment NumberOfValues
	// 4.2) SET: Sum = Sum + Value
	// 4.3) IF: MinValue > Value
	// 4.3.1) MinValue = Value
	// 4.4) IF: MaxValue < Value
	// 4.4.1) MaxValue = Value
	// 4.5) SET: variance = variance + (value^2)

	while(EOF != scanf("%lf", &value))
	{
		num++;
		sum += value;
		if(min > value)
			min = value;
		if(max < value)
			max = value;
		var += value * value;
	}

	// 5) REM: Calculate Variance
	// 5.1) SET: mean = sum / NumberOfValues
	// 5.2) SET: variance = variance / NumberOfValues
	// 5.3) SET: variance = variance - (mean^2)

	mean = sum / num;
	var /= num;
	var -= mean * mean;

	// 6) StdDev = sqrt(variance)

	sdev = sqrt(var);

	// 7) PUT: All statistical measures to screen.

	printf("\n"); // Carriage Return for input line after ^Z is entered.
	printf("\n"); // Print a blank line
	printf("STATISTICAL SUMMARY OF DATA\n");
	printf("Number of Data Values : %i\n", num);
	printf("Minimum Value = %f\n", min);
	printf("Maximun Value = %f\n", max);
	printf("Mean Value = %f\n", mean);
	printf("Sum of Values = %f\n", sum);
	printf("Variance = %f\n", var);
	printf("Standard Deviatoin = %f\n", sdev);

	// 8) PUT: Program Termination Message to screen.
	// 9) EXIT program

	printf("\n"); // Print a blank line
	printf("PROGRAM TERMINATED BY USER\n");
	return(0);
}

//== SUPPORT FUNCTIONS ====================================================
void PrintHeader(void)
{
	printf("========================================"
			 "=======================================\n");
	printf("Course....... %s-%i (%s %i)\n", COURSE, SECTION, TERM, YEAR);
	printf("Programmer... %s (%s)\n", PROGRAMMER, PROG_CODE);
	printf("Assignment... %s (Rev %i) (Source Code in %s)\n",
		ASSIGNMENT, REVISION, FILENAME);
	printf("Description.. %s\n", TITLE);
	printf("              %s\n", SUBTITLE);
	printf("========================================"
			 "=======================================\n");

	return;
}