function splitIntoSegmentsUntilGoodEnough()

in resources/perf.webkit.org/public/shared/statistics.js [546:578]

• 24 lines of code
• 6 McCabe index (conditional complexity)

    function splitIntoSegmentsUntilGoodEnough(values, BirgeAndMassartC) {
        if (values.length < 2)
            return [0, values.length];

        var matrix = new SampleVarianceUpperTriangularMatrix(values);

        var SchwarzCriterionBeta = Math.log1p(values.length - 1) / values.length;

        BirgeAndMassartC = BirgeAndMassartC || 2.5; // Suggested by the authors.
        var BirgeAndMassartPenalization = function (segmentCount) {
            return segmentCount * (1 + BirgeAndMassartC * Math.log1p(values.length / segmentCount - 1));
        }

        var segmentation;
        var minTotalCost = Infinity;
        var maxK = Math.min(50, values.length);

        for (var k = 1; k < maxK; k++) {
            var start = Date.now();
            var result = findOptimalSegmentation(values, matrix, k);
            var cost = result.cost / values.length;
            var penalty = SchwarzCriterionBeta * BirgeAndMassartPenalization(k);
            if (cost + penalty < minTotalCost) {
                minTotalCost = cost + penalty;
                segmentation = result.segmentation;
            } else
                maxK = Math.min(maxK, k + 3);
            if (Statistics.debuggingSegmentation)
                console.log('splitIntoSegmentsUntilGoodEnough', k, Date.now() - start, cost + penalty);
        }

        return segmentation;
    }