Thread: Printing A Histogram...

This code is for a dice simulator. Rolling 2 dice and printing out the results in the form of a histogram. The code runs fine. It's just that I don't want to see the number percentages with the asterisks. Does anyone know how to get rid of those numbers before the asterisk?
Example of my output:
2: 2 **
3: 6 ******
4: 10 **********

Example of how I want the output to be:
2: **
3: ******
4: **********

import java.util.*;
public class DiceSim {
	public static void main(String[] args) {
		Scanner Input = new Scanner(System.in);
 
		int[] frequency = new int [13]; //Declares the array
		int die, die2;
		int numbThrows;
		int asterisk;
		int total;
		double fractionOfReps;
 
		System.out.println("How many dice rolls would you like to simulate? ");
		numbThrows = Input.nextInt();
 
		//Roll the dice
		for (int i=1; i<=numbThrows; i++) {
			 die = (int)(Math.random()*6) + 1;
             die2 = (int)(Math.random()*6) + 1;
	         total = die + die2;  
	            frequency[total]++;    
		}
 
		System.out.println("DICE ROLLING SIMULATION RESULTS " + '\n' + "Each " + '\"' + "*" + '\"' + " represents 1% of the total number" +
				" of rolls.");
		System.out.println("Total number of rolls = " + numbThrows);
 
		//output dice rolls
		for (total=2; total<=numbThrows; total++)
		{ 
			System.out.print(
					" " + total  + ": " + frequency[total] + " ");
 
			fractionOfReps = (float) frequency[total] / numbThrows;
			asterisk = (int) Math.round(fractionOfReps * 100);
 
			for (int i=0; i<asterisk; i++)
			{
				System.out.print("*");
			}
			System.out.println();
		}
	}
}

I think the problem lies in this line..

System.out.print(
					" " + total  + ": " + frequency[total] + " ");

Can anyone help me?

Originally Posted by Nuggets

I think the problem lies in this line..

System.out.print(
					" " + total  + ": " + frequency[total] + " ");

Hello Nuggets!
I'm not sure but what if you remove frequency[total] from that code?

Originally Posted by andreas90

Hello Nuggets!
I'm not sure but what if you remove frequency[total] from that code?

Removing frequency[total] helped , as it got rid of those numbers. But then it added a 13 to the output. Do you know where that 13 came from?
Before with frequency[total] -
2: 2**
3: 5*****
4: 6******
5: 14**************
6: 11***********
7: 21*********************
8: 9*********
9: 9*********
10: 9*********
11: 12************
12: 2**
Without -
2: **
3: ****
4: ************
5: **************
6: *****************
7: ****************
8: **********
9: ************
10: ********
11: ***
12: **
13:

Can you post the updated code that gives you this output? And also what you input in the How many dice rolls would you like to simulate? question?

import java.util.*;
public class DiceSim {
	public static void main(String[] args) {
		Scanner Input = new Scanner(System.in);
 
		int[] frequency = new int [13]; //Declares the array
		int die, die2;
		int numbThrows;
		int asterisk;
		int total;
		double fractionOfReps;
 
		System.out.println("How many dice rolls would you like to simulate? ");
		numbThrows = Input.nextInt();
 
		//Roll the dice
		for (int i=1; i<=numbThrows; i++) {
			 die = (int)(Math.random()*6) + 1;
             die2 = (int)(Math.random()*6) + 1;
	         total = die + die2;  
	            frequency[total]++;    
		}
 
		System.out.println("DICE ROLLING SIMULATION RESULTS " + '\n' + "Each " + '\"' + "*" + '\"' + " represents 1% of the total number" +
				" of rolls.");
		System.out.println("Total number of rolls = " + numbThrows);
 
		//output dice rolls
		for (total=2; total<=numbThrows; total++)
		{ 
			System.out.print(
					" " + total  + ": ");
 
			fractionOfReps = (float) frequency[total] / numbThrows;
			asterisk = (int) Math.round(fractionOfReps * 100);
 
			for (int i=0; i<asterisk; i++)
			{
				System.out.print("*");
			}
			System.out.println();
		}
	}
}

I input 100 dice rolls to simulate. Output is this:
DICE ROLLING SIMULATION RESULTS
Each "*" represents 1% of the total number of rolls.
Total number of rolls = 100
2: ****
3: ********
4: *******
5: ******
6: **************
7: ******************
8: *****************
9: ************
10: *********
11: ***
12: **
13:

for (total=2; total<=numbThrows; total++)

In the above code total goes up to numbThrows. And then

fractionOfReps = (float) frequency[total] / numbThrows;

So when total equals 13 your program stops and you should face an ArrayIndexOutOfBoundsException (don't you?) because frequency[] has 13 indexes (from 0 to 12) and you try to access index 13.

Unfortunately, i can't help you with that. I'm not at all familiar with the Eclipse IDE and how it works.