# How would I add standard deviation to my program? Please help.

Printable View

• 05-13-2012, 03:24 PM
WilsonGTI45
How would I add standard deviation to my program? Please help.
New to Java and having trouble adding standard deviation to my program. Please help, it would be greatly appreciated!

package sales.report;

import java.util.Scanner;
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/

/**
*
* @author MILFHUNTER
*/
public class SalesReporter {
private double highestSales;
private double averageSales;
private SalesAssociate[] team;

private int numberOfAssociates;

public void getData()
{
Scanner keyboard = new Scanner(System.in);
System.out.println("Enter number of sales associates:");
numberOfAssociates = keyboard.nextInt();
team = new SalesAssociate[numberOfAssociates +1 ];

for (int i = 1; i <= numberOfAssociates; i++)
{
team[i] = new SalesAssociate();
System.out.println("Enter data for associate " + i);
team[i].readInput();
System.out.println();
}
}
public void computeStats()
{
double nextSales = team[1].getSales();
highestSales = nextSales;
double sum = nextSales;
for (int i = 2; i <= numberOfAssociates; i++)
{
nextSales = team[i].getSales();
sum = sum + nextSales;
if (nextSales > highestSales)
highestSales = nextSales;
}
averageSales = sum / numberOfAssociates;
}
public void displayResults()
{
System.out.println("Average sales per associate is \$" +
averageSales);
System.out.println("The highest sales figure is \$" +
highestSales);
System.out.println();
System.out.println("The following had the highest sales");
for (int i = 1; i <= numberOfAssociates; i++)
{
double nextSales = team[i].getSales();
if (nextSales == highestSales)
{
team[i].writeOutput();
System.out.println("\$" + (nextSales-averageSales)
+ "above the average.");
System.out.println();

}
}
System.out.println("The rest performed as follows");
for (int i = 1; i <= numberOfAssociates; i++)
{
double nextSales = team[i].getSales();
if (team[i].getSales() != highestSales)
{
team[i].writeOutput();
if (nextSales >= averageSales)
System.out.println("\$" + (nextSales-
averageSales) + "above the average.");
else
System.out.println("\$" + (averageSales -
nextSales) + "below the average.");
System.out.println();

}
}
}
public static void main(String[] args)
{
SalesReporter clerk = new SalesReporter();
clerk.getData();
clerk.computeStats();
clerk.displayResults();

}
}
• 05-13-2012, 04:49 PM
DarrylBurke
Re: How would I add standard deviation to my program? Please help.
• 05-13-2012, 05:03 PM
Norm
Re: How would I add standard deviation to my program? Please help.
Can you explain where your formula is for computing the desired value?
• 05-13-2012, 05:10 PM
WilsonGTI45
Re: How would I add standard deviation to my program? Please help.
public void computeStats()
{
double nextSales = team[1].getSales();
highestSales = nextSales;
double sum = nextSales;
for (int i = 2; i <= numberOfAssociates; i++)
{
nextSales = team[i].getSales();
sum = sum + nextSales;
if (nextSales > highestSales)
highestSales = nextSales;
}
averageSales = sum / numberOfAssociates;
sum = 0;
for ( int i = 1; i<= numberOfAssociates; i++)
{double diff = (averageSales-team[i].getSales());
sum = sum + diff*diff;
}
double variance = sum / ( numberOfAssociates-1 );
stdDev = sqrt (variance)

So I have worked on it some more in this is what I have...I get an error message(erroneous symbol) for stdDev = sqrt (variance)
• 05-13-2012, 05:12 PM
Norm
Re: How would I add standard deviation to my program? Please help.
Quote:

I get an error message
Please post the full text of the error message.
• 05-13-2012, 05:15 PM
WilsonGTI45
Re: How would I add standard deviation to my program? Please help.
Exception in thread "main" java.lang.RuntimeException: Uncompilable source code - Erroneous sym type: sqrt
at sales.report.SalesReporter.computeStats(SalesRepor ter.java:59)
at sales.report.SalesReporter.main(SalesReporter.java :104)
Java Result: 1
• 05-13-2012, 05:25 PM
WilsonGTI45
Re: How would I add standard deviation to my program? Please help.
Ok I fixed that...

should be Math.sqrt instead of sqrt

Having trouble displaying in results now when i run the program
• 05-13-2012, 05:45 PM
DarrylBurke
Re: How would I add standard deviation to my program? Please help.
WilsonGTI45, I posted three links for you. I expect you to go through them.

db