[removed] remove outlier from an array?

Question

values = [8160,8160,6160,22684,0,0,60720,1380,1380,57128]

how can I remove outliers like 0, 57218, 60720 and 22684?

Is there a library whic

Answer 1

Here is the implementation to filter upper outliers from a given collection. This approach follows a similar methodology as the provided answers above.

The if case will be checking the length of collection if it is 4n or 4n + 1. In that case, we need to get an average of two elements to have our quartiles.

Otherwise, in cases of 4n + 2 and 4n + 3, we directly can access the upper/lower quartile.

const outlierDetector = collection => {
    const size = collection.length;

    let q1, q3;

    if (size < 2) {
        return collection;
    }

    const sortedCollection = collection.slice().sort((a, b) => a - b);

    if ((size - 1) / 4 % 1 === 0 || size / 4 % 1 === 0) {
        q1 = 1 / 2 * (sortedCollection[Math.floor(size / 4) - 1] + sortedCollection[Math.floor(size / 4)]);
        q3 = 1 / 2 * (sortedCollection[Math.ceil(size * 3 / 4) - 1] + sortedCollection[Math.ceil(size * 3 / 4)]);
    } else {
        q1 = sortedCollection[Math.floor(size / 4)];
        q3 = sortedCollection[Math.floor(size * 3 / 4)];
    }

    const iqr = q3 - q1;
    const maxValue = q3 + iqr * 1.5;

    return sortedCollection.filter(value => value >= maxValue);
};