/** * Calculate the sum of a 2D array. * * @param arr * @return the sum */ public static double sum(double[][] arr) { double sum = 0; for (int i = 0; i < arr.length; i++) sum += sum(arr[i]); return sum; }
/** * Calculate the sum of the absolute values of a 2D array. * * @param arr * @return the sum absolute values */ public static double sumAbs(double[][] arr) { double sum = 0; for (int i = 0; i < arr.length; i++) sum += sumAbs(arr[i]); return sum; }
/** * Calculate the sum of the squared values of a 2D array. * * @param arr * @return sum of squares */ public static double sumSq(double[][] arr) { double sum = 0; for (int i = 0; i < arr.length; i++) sum += sumSq(arr[i]); return sum; }
/** * Calculate the sample standard deviation of a 1D array. Calls * {@link DoubleArrayStatsUtils#var(double[])} and does a Math.sqrt. * * @param arr * @return the standard deviation */ public static double std(double[] arr) { return Math.sqrt(var(arr)); }
@Override public double[] normalise(double[] vector) { final double mean = DoubleArrayStatsUtils.mean(vector); vector = ArrayUtils.subtract(vector, mean); return vector; }
residualEstimator.computeResiduals(data, errors); final double medianError = DoubleArrayStatsUtils.median(errors); if (medianError < bestMedianError) { bestMedianError = medianError;
/** * Calculate the sample standard deviation of a 2D array. Calls * {@link DoubleArrayStatsUtils#var(double[][])} and does a Math.sqrt. * * @param arr * @return the standard deviation */ public static double std(double[][] arr) { return Math.sqrt(var(arr)); }