Java: Data Science Made Easy

Using ArrayLists to find multiple modes

In the first approach, we modify the code used in the last example to use an ArrayList class. We will create two ArrayLists, one to hold the unique numbers within the dataset and one to hold the count of each number. We also need a tempMode variable, which we use next:

ArrayList<Integer> modeCount = new ArrayList<Integer>();  ArrayList<Double> mode = new ArrayList<Double>();   int tempMode = 0; 

Next, we will loop through the array and test for each value in our mode list. If the value is not found in the list, we add it to mode and set the same position in modeCount to 1. If the value is found, we increment the same position in modeCount by 1:

for (double testValue : testData){  int loc = mode.indexOf(testValue); ...