differenceOrd function

List<double> differenceOrd(
  1. List<double> x,
  2. int d
)

Differencing and inverse differencing (d)

Implementation

List<double> differenceOrd(List<double> x, int d) {
  if (d <= 0) return List<double>.from(x);
  var y = List<double>.from(x);
  for (int k = 0; k < d; k++) {
    final n = y.length;
    final z = List<double>.filled(n - 1, 0.0);
    for (int i = 1; i < n; i++) z[i - 1] = y[i] - y[i - 1];
    y = z;
  }
  return y;
}