uf3.representation.bspline.generate_lammps_knots

generate_lammps_knots(r_min: float, r_max: float, n_intervals: int, sequence: bool = True) → numpy.ndarray[source]

Generate knot points or knot sequence using LAMMPS convention of distance^2. This scheme yields somewhat higher resolution at larger distances and somewhat lower resolution at smaller distances. Since speed is mostly unaffected by the number of basis functions, due to the local support, a high value of n_intervals ensures resolution while ensuring expected behavior in LAMMPS.

Parameters

  • r_min (float) – lower-bound for knot points.

  • r_max (float) – upper-bound for knot points.

  • n_intervals (int) – number of unique intervals in the knot sequence, i.e. n_intervals + 1 samples will be taken between r_min and r_max.

  • sequence (bool) – whether to repeat ends to yield knot sequence.

Returns

knot points or knot sequence.

Return type

knots (np.ndarray)