MathUtil { public static double[] trimZeroTail(final double[] data) { return Arrays.copyOfRange(data, 0, countNonZeroBeginning(data)); }  static double sum(final List<? extends Number> list); static double[] listToArray(final List<? extends Number> list); static double median(final List<Double> list); static double median(final double[] list); static DescriptiveStatistics getStatistics(final List<Double> list); static DescriptiveStatistics getStatistics(final double[] list); static double mean(final List<Double> list); static double variance(final List<Double> list); static double stDev(final List<Double> list); static double mad(final double[] data); static double iqr(final double[] data); static int countNonZeroBeginning(final double[] data); static int countShortestRow(final double[][] data); static double[] trimZeroTail(final double[] data); static double[] getLoessParameterEstimates(final double[] y); static SimpleRegression createLinearRegression(final double[] x,
			final double[] y); static OLSMultipleLinearRegression createLinearRegression(
			final double[][] x, final double[] y); static SimpleRegression createWeigthedLinearRegression(
			final double[] x, final double[] y, final double[] weigths); static double[] getRobustLoessParameterEstimates(final double[] y); static double[] getTricubeWeigts(final int n); static double[] getTricubeBisquareWeigts(final double[] residuals); static double[] abs(final double[] data);  }
@Test public void testTrimZeroTail() { assertArrayEquals(NON_ZERO_TAIL, MathUtil.trimZeroTail(DATA4), 0); }