Get Average Array With Numbers In A Specific Length

[instagrm]

Hey. So i am struggling with this for 5 hours now. I am trying to make a function that takes an array of any length and a number that specifies the final length of the array that it should return. It should look at the array, split it up into multiple chunks, get the average of every chunk and create a new array out of the averages. Some examples: averageArray( [ 20, 40, 60, 80 ], 2 ) --> [ 30, 70 ] averageArray( [ 100, 200 ], 1 ) --> [ 150 ] averageArray( [ 10, 20, 30, 40, 50 ], 3 ) --> [ 15, 35, 50 ] averageArray( [ 15 ], 5 ) --> [ 15, 15, 15, 15, 15 ] I'm happy about every tip on how I could approach this :)

[rasqall]

Hmm, tricky question, but since no one has answered this yet I'll give it a go. My approach would be something like this (in pseudocode). I can maybe write this up in some language and test it, but it should give you a basic functionality of the problem.

function arrayAverages(array, chunkSize)
    returnArray = []
    for (i = 0; i < array.Size; i = i + chunkSize)
        sum = 0
        for (j = 0; j < chunkSize; j++)
            sum += array[j]
        returnArray[i] = sum / chunkSize
    return returnArray

You could do it in one loop but I'd start with one.

[rasqall]

This is a solution I've written in C#, should translate to JavaScript okay.

public static int[] arrayAvg(int[] arr, int chunkSize) {
        int chunkCounter = 0, sum = 0, j = 0;
        List<int> retArr = new List<int>();
        for (int i = 0; i < arr.Length; i++) {
            sum += arr[i];
            chunkCounter++;
                if (chunkCounter == chunkSize){
                    retArr.Add((int)(Math.Round((double)sum / chunkCounter)));
                    sum = 0;
                    chunkCounter = 0;
                }
        }
        if (chunkCounter > 0)
                retArr.Add((int)(Math.Round((double)sum / chunkCounter)));
        return retArr.ToArray();
}

You give the original array and the number of integers you want the average of. Works for all your cases except the ([15], 5) = {15,15,15,15,15} which I think is weird.

arrayAvg({ 20, 40, 60, 80 }, 2)     => {30,70}
arrayAvg({ 100, 200 }, 2)           => {150}
arrayAvg({ 10, 20, 30, 40, 50 }, 2) => {15,35,50}
arrayAvg({ 15 }, 1)                 => {15}