differenceOrdinary function

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

============================== DIFFERENCING / INVERSION HELPERS

Nonseasonal differencing: apply d times

Implementation

/// Nonseasonal differencing: apply d times
List<double> differenceOrdinary(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 ny = <double>[];
    for (int i=1; i<y.length; i++) ny.add(y[i]-y[i-1]);
    y = ny;
  }
  return y;
}