How to find the frequency of occurrence of a number or a string in an array

yousufalin

Hello everyone,

    int [] number= {4,5,6,3,5,3,5,6,6,8};
    String [] animal= {cat,dog,rat,cat,cat,dog,dog,dog,cat,rat};
    void setup(){
    size(800,800);
    smooth();

    }

    void draw(){
    background(0);

    }

I would like to know how can I write a code that will find me the repeated occurrence of each of the number/string in the array.

my aim is to list the numbers and strings as follows

Number 3 = 2 Number 4 = 1 Number 5 = 3 Number 6 = 3 Number 8 = 1

cat = 4 Dog = 4 rat =2

Any help will be greatly appreciated.

Many thanks in advance :)

TfGuy44

I hand you a bag of marbles and ask you how many of each color are in the bag.

How do you, as a person, solve this problem?

Can you describe the process you use?

Using that description, can you explain the process in a way that my pet robot can understand?

Try your hand at this first - post your results. Do not jump right into code. English can also be used to describe directions.

lolnyancats

make a variable called numDog,numRat,numCat have a for loop that runs through that entire array and searches for an element and then increase that variable by 1. You can then print it in the draw() method

yousufalin

Dear TfGuy44, Thank you for your reply, :) and sorry for my less described, informed question.

So i tried breaking down the task in to the following steps

I have an array of numbers for example: 1,2,3,3,4,3,4,5,2 I wanted to group the repeating same numbers together and count how many time each of the numbers repeat in the given array. then making a table with two columns, showing the numbers in the array on one side and their repeating occurrence on the other side

I hope this description makes sense :)

yousufalin

Dear Lonlyancats,

Thank you so much for your help! :) shall try doing it, Although I am a beginner in coding

GoToLoop

A possible solution is simply create some HashMap to store the pair {key : repeats}:
https://processing.org/reference/HashMap.html

For the int[] array, the pair is Map<Integer, Integer>:
final Map<Integer, Integer> intAmount = new HashMap<Integer, Integer>();

And for the String[] array, it is now Map<String, Integer>:
final Map<String, Integer> petAmount = new HashMap<String, Integer>();

However for Map<String, Integer>, Processing got a more simplified container called IntDict:
https://processing.org/reference/IntDict.html

So let's use it for this specific Map<String, Integer> case instead:
final IntDict petAmount = new IntDict();

For the Map container, we're gonna need its get() & put() methods:
http://docs.oracle.com/javase/8/docs/api/java/util/Map.html#get-java.lang.Object-
http://docs.oracle.com/javase/8/docs/api/java/util/Map.html#put-K-V-

And the correspong 1s for IntDict are get() & set():
https://processing.org/reference/IntDict_get_.html
https://processing.org/reference/IntDict_set_.html

And finally, here's the full solution. Any further doubts just ask here again: O:-)

P.S.: Newer version replacing IntDict's get() & set() methods w/ increment(): :P
https://processing.org/reference/IntDict_increment_.html

// forum.processing.org/two/discussion/11275/
// how-to-find-the-frequency-of-occurrence-of-a-number-or-a-string-in-an-array

// 2015-Jun-11

import java.util.Map;

final Map<Integer, Integer> intAmount = new HashMap<Integer, Integer>();
final IntDict petAmount = new IntDict();

static final int[] INTS = {
  4, 5, 6, 3, 5, 3, 5, 6, 6, 8
};

static final String[] PETS = {
  "cat", "dog", "rat", "cat", "cat", "dog", "dog", "dog", "cat", "rat"
};

void setup() {
  for (Integer i : INTS) {
    Integer qty = intAmount.get(i);
    intAmount.put(i, qty == null? 1 : qty + 1);
  }

  // for (String s : PETS) {
  //   int qty = petAmount.get(s, 0);
  //   petAmount.set(s, qty + 1);
  // }

  for (String s : PETS)  petAmount.increment(s);

  println(intAmount);
  println(petAmount);

  exit();
}

P.S.: For better code format in this forum, read this article please:
http://forum.processing.org/two/discussion/8045/how-to-format-code-and-text

yousufalin

Thank you so much GoToLoop!!!

Now I will sit and learn this :)