JavaScript Template Comparison

Question

I am working on a little machine learning theoretical algorithm using nodeJs. My goal is to compare many array patterns with a single source pattern , and then return them as a percentage. For example, pattern1 could be 80%, similar to the source pattern.

What could be the best method for determining percent similarity for one array to another?

What have I done so far ..

//source   
var soureSequence = [0.53,0.55,0.50,0.40,0.50,0.52,0.58,0.60]

//patterns to compare
var sequence1 = [0.53,0.54,0.49,0.40,0.50,0.52,0.58,0.60]
var sequence2 = [0.53,0.55,0.50,0.42,0.50,0.53,0.57,0.62]

Since I chose the percentage result, I decided that I should base the original template from the percentage change from the first value to the second value in the array.

 var percentChange = (firstVal, secondVal) => {
        var pChange = ((parseFloat(secondVal) - firstVal) / 
         Math.abs(firstVal)) * 100.00;

        //To avoid NaN , Infinity , and Zero

        if(!pChange || pChange == 0){
            return 0.00000001
        }
        return pChange;
    }

Here I will generate the source template from the source sequence

       var storePattern = function(sequence){
           var pattern = [];
           for(var i = 0 ; i < sequence.length ; i++){
               let $change = percentChange(sequence[i] , sequence[i + 1]);
               if(i != sequence.length && $change ){
                    pattern.push($change)
                }
            }
    return pattern;
     }



   var sourcePattern = storePattern(soureSequence);

Now I will create more models for comparison

   var testPattern1 = storePattern(sequence1);
   var testPattern2 = storePattern(sequence2);

Below is my comparison function

 var processPattern = function(source , target){
    var simularityArray = [];

    for(var i = 0 ; i < target.length ; i++){
        //Compare percent change at indexof testPattern to sourcePattern of same index
        let change = Math.abs(percentChange(target[i] , source[i]));
        simularityArray.push(100.00 - change);
    }

    var rating = simularityArray.reduce((a,b) => {
        return a + b
    });

    //returns percent rating based of average of similarity pattern

    rating = rating / parseFloat(source.length + ".00");
    return rating;
}

Now I can try to appreciate the similarities

var similarityOfTest1 = processPattern(sourcePattern , testPattern1)

, .. 0.50, 0.52.. 0,20, 0,22, , .. → 0,02

, .

. !

Answer 1

, .

//patterns to compare
var sequence1 = [0.53,0.54,0.49,0.40,0.50,0.52,0.58,0.60]
var sequence2 = [0.53,0.55,0.50,0.42,0.50,0.53,0.57,0.62]

function diff(sequence){
var soureSequence = [0.53,0.55,0.50,0.40,0.50,0.52,0.58,0.60]
   var delta = soureSequence.reduce(function (r, a, i, aa) {
        i && r.push(a - sequence[i]);
        return r;
    }, []),
    average = delta.reduce(function (a, b) { return a + b; }) / delta.length;
    
    return {delta:delta, average:average}
}
console.log('sequence1',diff(sequence1));
console.log('sequence2',diff(sequence2));

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Answer 2

, () ex. , , , ( ). Rosetta dot product JavaScript,

// dotProduct :: [Int] -> [Int] -> Int
const dotProduct = (xs, ys) => {
    const sum = xs => xs ? xs.reduce((a, b) => a + b, 0) : undefined;

    return xs.length === ys.length ? (
        sum(zipWith((a, b) => a * b, xs, ys))
    ) : undefined;
}

// zipWith :: (a -> b -> c) -> [a] -> [b] -> [c]
const zipWith = (f, xs, ys) => {
    const ny = ys.length;
    return (xs.length <= ny ? xs : xs.slice(0, ny))
        .map((x, i) => f(x, ys[i]));
}

,

const score1 = dotProduct(sourceSequence, sequence1);
const score2 = dotProduct(sourceSequence, sequence2);

, SourceSequence.

Answer 3

, . , , diff .

, , ( ) .

, diff. , , .

Answer 4

, . , , . , .

function check([x,...xs],[y,...ys], state = {sumSource: 0, sumDiff: 0}){
  state.sumSource += x;
  state.sumDiff += Math.abs(x-y);
  return xs.length ? check(xs,ys,state) : (100 - 100 * state.sumDiff / state.sumSource).toFixed(4) + "% similarity";
}

var soureSequence = [0.53,0.55,0.50,0.40,0.50,0.52,0.58,0.60],
    sequence1     = [0.53,0.54,0.49,0.40,0.50,0.52,0.58,0.60],
    sequence2     = [0.53,0.55,0.50,0.42,0.50,0.53,0.57,0.62];

console.log(check(soureSequence,sequence1));
console.log(check(soureSequence,sequence2));

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