Tukukkk

I want to detect the interval between time points. I want to ignore some anomalies if there are. The idea is choose some random samples and try to detect what is the interval between points in most cases.

import java.util.Arrays;

import java.util.Random;



public class Testing {



    private static int RANDOM_POINT_COUNT = 5;



    static private long getAverageInterval(long times, boolean useSampling) {



        long diffs;



        if (useSampling && times.length > 2 * RANDOM_POINT_COUNT) {

            diffs = calculateAverageRandomly(times, RANDOM_POINT_COUNT);

        } else {

            diffs = calculateAverage(times);

        }



        long sortedDiffs = Arrays.copyOf(diffs, diffs.length);

        Arrays.sort(sortedDiffs);

        final long interval = sortedDiffs[sortedDiffs.length / 2];

        return interval;

    }



    static private long calculateAverage(long times) {



        long diffs = new long[times.length - 1];



        for (int i = times.length - 2; i >= 0; --i) {

            diffs[i] = Math.abs(times[i] - times[i + 1]);

        }



        return diffs;

    }



    static private long calculateAverageRandomly(long times, int count) {



        assert times.length > 1;



        if (times.length == 2) {

            return new long {times[1] - times[0]};

        }



        long diffs = new long[2*count];

        int partCount = (int) Math.round(times.length*1.0/count);

        Random rn = new Random();

        int currentIndex = 0;



        for(int i = times.length - partCount-1; i >= 0 && currentIndex < diffs.length; i-= partCount) {



            int index =  rn.nextInt(partCount) +i;



            if(index == 0) {

                index = 1;

            }



            diffs[currentIndex] = times[index+1] - times[index];

            ++currentIndex;

            diffs[currentIndex] = times[index] - times[index - 1];

            ++currentIndex;

        }

        return diffs;

    }



    public static void main(String args) {

        final long t = { 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 61/*anomaly*/ };

        final long result = Testing.getAverageInterval(t, true);

        System.out.println(result);



        if(result != 5) {

            new RuntimeException("Excepted result is 5");

        }



        final long t1 = { 1, 2, 3, /*4,*/ 5, 6 /*7,*/, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, /*18,*/ 19 };



        final long result1 = Testing.getAverageInterval(t1, true);

        System.out.println(result1);

        if(result1 != 1) {

            new RuntimeException("Excepted result is 1");

        }

    }

}