How to use

q1

method

in

smile.sort.QuickSelect

/**
 * Find the first quantile (p = 1/4) of an array of type float. The input array will
 * be rearranged.
 */
public static float q1(float[] a) {
  return QuickSelect.q1(a);
}

/**
 * Find the first quantile (p = 1/4) of an array of type int. The input array will
 * be rearranged.
 */
public static int q1(int[] a) {
  return QuickSelect.q1(a);
}

/**
 * Find the first quantile (p = 1/4) of an array of type double. The input array will
 * be rearranged.
 */
public static double q1(double[] a) {
  return QuickSelect.q1(a);
}

/**
 * Find the first quantile (p = 1/4) of an array of type double. The input array will
 * be rearranged.
 */
public static <T extends Comparable<? super T>> T q1(T[] a) {
  return QuickSelect.q1(a);
}

@Override
public void learn(Attribute[] attributes, double[][] data) {
  int n = data.length;
  int p = data[0].length;
  mu = new double[p];
  std = new double[p];
  double[] x = new double[n];
  for (int j = 0; j < p; j++) {
    if (attributes[j].getType() != Attribute.Type.NUMERIC) {
      mu[j] = Double.NaN;
    } else {
      for (int i = 0; i < n; i++) {
        x[i] = data[i][j];
      }
      mu[j] = QuickSelect.median(x);
      std[j] = QuickSelect.q3(x) - QuickSelect.q1(x);
      if (Math.isZero(std[j])) {
        throw new IllegalArgumentException("Column " + j + " has constant values between Q1 and Q3.");
      }
    }
  }
}