Support Resistance Algorithm - Technical analysis

Question

I have an intra-day chart and I am trying to figure out how to calculate support and resistance levels, anyone knows an algorithm for doing that, or a good starting point?

Answer 1

I'm not sure if it's really "Support & Resistance" detection but what about this:

function getRanges(_nums=[], _diff=1, percent=true) {
    let nums = [..._nums];
    nums.sort((a,b) => a-b);
    
    const ranges = [];
    for (let i=0; i isInRange(j, num-diff, num+diff) );
        if (range.length) {
            ranges.push(range);
            nums = nums.slice(range.length);
            i = -1;
        }
    }
    return ranges;
}

function perc(percent, n) {
    return n * (percent * 0.01);
}
function isInRange(n, min, max) {
    return n >= min && n <= max;
}

So let's say you have an array of close prices:

const nums = [12, 14, 15, 17, 18, 19, 19, 21, 28, 29, 30, 30, 31, 32, 34, 34, 36, 39, 43, 44, 48, 48, 48, 51, 52, 58, 60, 61, 67, 68, 69, 73, 73, 75, 87, 89, 94, 95, 96, 98];

and you want to kinda split the numbers by an amount, like difference of 5 (or 5%), then you would get back a result array like this:

const ranges = getRanges(nums, 5, false) // ranges of -5  to +5
/* [
    [12, 14, 15, 17]
    [18, 19, 19, 21]
    [28, 29, 30, 30, 31, 32]
    [34, 34, 36, 39]
    [43, 44, 48, 48, 48]
    [51, 52]
    [58, 60, 61]
    [67, 68, 69]
    [73, 73, 75]
    [87, 89]
    [94, 95, 96, 98]
]
*/

// or like
//const ranges = getRanges(nums, 5, true)  // ranges of -5% to +5%

therefore the more length a range has, the more important of a support/resistance area it is.

(again: not sure if this could be classified as "Support & Resistance")