how to create a histogram in java

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how to convert numbers into symbols in java? for example instead of 2 to **, or 3 to *** etc.

How can I convert numbers into a histogram ? The histogram should display the bar graphs from 2-12 based upon how many times that value was rolled. currently my output is like the second pic but is suppose to look like the first one. thanks. like this: enter image description here

    public static void main(String[] args) {
    // TODO code application logic here
    System.out.print("Please enter how many times you want to roll two dice?");
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    int [] rolls = new int[n];

    Random r1 = new Random();
    Random r2 = new Random();

    int dice1;
    int dice2;

    int two = 0;
    int three = 0;
    int four = 0;
    int five = 0;
     int six = 0;
    int seven = 0;
    int eight = 0;
    int nine = 0;
     int ten = 0;
    int eleven = 0;
    int twelve = 0;

    for (int roll=0; roll < rolls.length; roll++)
    {
         dice2 = r2.nextInt(6)+1;
         dice1 = r1.nextInt(6)+1;
         System.out.println(roll + " The first dice rolled a " + dice1 + " the second dice rolled a " + dice2);

         int sum;
         sum = dice1 + dice2;

         if (sum == 2)
             two++;
         if (sum == 3)
             three++;
         if (sum == 4)
             four++;
         if (sum == 5)
             five++;
         if (sum == 6)
             six++;
         if (sum == 7)
             seven++;
         if (sum == 8)
             eight++;
         if (sum == 9)
             nine++;
         if (sum == 10)
             ten++;
         if (sum == 11)
             eleven++;
         if (sum == 12)
             twelve++;

    }
    System.out.println("Histogram of rolls:" );  
    System.out.println("2 occurred " + two + " times");
    System.out.println("3 occurred " + three + " times");
    System.out.println("4 occurred " + four + " times");
    System.out.println("5 occurred " + five + " times");
    System.out.println("6 occurred " + six + " times");
    System.out.println("7 occurred " + seven + " times");
    System.out.println("8 occurred " + eight + " times");
    System.out.println("9 occurred " + nine + " times");
    System.out.println("10 occurred " + ten + " times");
    System.out.println("11 occurred " + eleven + " times");
    System.out.println("12 occurred " + twelve + " times");




}

}

I assume the #/asterisks is the #/occurrences (in your example, `3: *****`). If so, just 1) define a string 12 asterisks long, and 2) take the substring(), length 0..12, for each line of your histogram. PS: I'd use an int[] array instead of twelve separate variables "one", "two", ... — paulsm4, Oct 28 '12 at 06:47
already asked this question, with 75 rep. you could have start a bounty. — Mordechai, Oct 28 '12 at 07:22

score 5 · Accepted Answer · edited Dec 04 '14 at 05:12

Here are some various bits of code you can use to accomplish this.

Create array

int[] histogram = new int[13];

Increment a position in the array

histogram[id]++;

Print histogram

System.out.println("Histogram of rolls:" );
printHistogram(histogram);

Here are some helper functions as well.

private void printHistogram(int[] array) {
     for (int range = 0; range < array.length; range++) {
        String label = range + " : ";
        System.out.println(label + convertToStars(array[range]));
    }
}

private String convertToStars(int num) {
    StringBuilder builder = new StringBuilder();
    for (int j = 0; j < num; j++) {
        builder.append('*');
    }
    return builder.toString();
}

Code should be modified as needed.

how to create a histogram in java

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