Example usage for java.util TreeSet pollFirst

Introduction

In this page you can find the example usage for java.util TreeSet pollFirst.

Prototype

public E pollFirst()

Source Link

Usage

From source file:ro.hasna.ts.math.representation.AdaptivePiecewiseConstantApproximation.java

@Override
public MeanLastPair[] transform(double[] values) {
    int length = values.length;
    if (length < 2 * segments) {
        throw new ArrayLengthIsTooSmallException(length, 2 * segments, true);
    }//w w w  . j a v  a 2s .c  om
    int numberOfSegments = length / 2;

    // create segments with two values
    Segment first = createSegments(values, length);

    if (numberOfSegments > segments) {
        // compute error by unifying current segment with the next segment
        TreeSet<Segment> set = createSegmentsSet(values, first);

        // unify concurrent segments with minimum error
        while (numberOfSegments > segments) {
            Segment minSegment = set.pollFirst();
            minSegment.mean = getUnifiedMean(minSegment, minSegment.next);
            minSegment.error = getUnifiedError(minSegment, minSegment.next, values, minSegment.mean);
            minSegment.end = minSegment.next.end;

            deleteSubsequentSegment(minSegment, set);

            if (minSegment.next != null) {
                double mean = getUnifiedMean(minSegment, minSegment.next);
                minSegment.errorWithNext = getUnifiedError(minSegment, minSegment.next, values, mean);
                set.add(minSegment);
            }

            if (minSegment.prev != null) {
                set.remove(minSegment.prev);

                double mean = getUnifiedMean(minSegment.prev, minSegment);
                minSegment.prev.errorWithNext = getUnifiedError(minSegment.prev, minSegment, values, mean);

                set.add(minSegment.prev);
            }

            numberOfSegments--;
        }
    }

    return getMeanLastPairs(first, numberOfSegments);
}