Geometric Mean

[t3kn0]

Hi folks, can anyone help me with a problem?

I have a class below to work out the average of a series of numbers. Can anyone give me a clue on how to extend this example so that it also prints the geometric mean of the numbers. The geometric mean of n numbers is the n-th root of their product. Using
the Math.pow function to calculate the n-th root.

All hints, solutions appreciated. code below:

// Average
// Accept a series of numbers and display average (0 ends input and does not count)


import javax.swing.JOptionPane; // Required for Windows boxes

public class Average
{
public static void main(String args[])
{
// Declare variables
int[] digit = new int[100];
int[] nums;
String input = "";
String output = "";
int count = 0;
int index = 9;
int amount = 0;
int sum = 0;
int avg = 0;

// Request input
while(index != 0)
{
input = JOptionPane.showInputDialog(null, "Enter an Integer", "Average Calculator", JOptionPane.QUESTION_MESSAGE);
index = Integer.parseInt(input);
digit[count] = index;
count++;

}

// Calculate average

for (count = 0; count < digit.length; count++) // for every element in digit[]
{
if (digit[count] > 0) // only if not equal to 0
{
amount++; // running total of live numbers
}

}

nums = new int[amount]; // assign new length to hold stored numbers
for (int i = 0; i < nums.length; i++)
{
nums[i] = digit[i]; // transfer only live values
sum += nums[i]; // get total of live values
}
if(amount > 0) // don't divide by zero pc wont like it!
{
avg = (sum / amount); // Finally get the average integer
}
else
{
JOptionPane.showMessageDialog(null, "You Just Entered 0", "Nothing to calculate", JOptionPane.ERROR_MESSAGE);
System.exit(0); // Break out of program
}


// Create output
output = "The sum of the integers you entered is: " + sum + "\nThe average integer you entered is: " + avg;

// Output result
JOptionPane.showMessageDialog(null, output, "Average Calculator", JOptionPane.INFORMATION_MESSAGE);

// End program
System.exit(0);
}
}

[Kram]

well if i understand the geometric mean correctly, then something like this should be ok

noOfNumbers = //get the number of numbers entered
double multiplyResult = 1.0;
double geoMean;

//this will multiply all numbers entered in by user
for(int i=0;i<digit.length;i++){
  multiplyResult = multiplyResult*digit[i];
}

geoMean = Math.pow(multiplyResult, (1/noOfNumbers));

this is NOT tested, just an idea about how to go about it, you could change the code all you want, but it should be on the right track

[t3kn0]

Cheers pal.

haven't had time to test it yet but looks logical.

-- Life is so much easier when someone else has the answer --

[Kram]

no problem matey