splinebox.spline_curves.HermiteSpline.

distance

HermiteSpline.distance(points, return_t=False)

Computes the distance of point from the spline.

Parameters:

pointsnumpy.array

Array with the coordinates of one or multiple point(s).

return_tbool

Whether to return the paramter t of the spline. spline(t) gives the location on the spline closest to the point.

Returns:

distancefloat

The distance between the point and the spline.

tfloat

Only returned if return_t=True. This is the parameter corresponding to the location on the spline closest to the point.

Examples

>>> import splinebox
>>> import numpy as np
>>> import matplotlib.pyplot as plt

We start by creating a spline

>>> spline = splinebox.Spline(M=4, basis_function=splinebox.B3(), closed=False)
>>> spline.control_points = np.array([[0, 0], [1, 1], [2, 0], [3, 1], [4, 0], [5, 1]])

We can compute the distance to a point as follows:

>>> point = np.array([2.1, 0.8])
>>> distance, closest_t = spline.distance(point, return_t=True)

To find the closest point on the spline we simply evaluate the spline at the closest_t

>>> closest_point = spline(closest_t)

The result can be checked in a plot:

>>> plt.plot(vals[:, 0], vals[:, 1])
>>> plt.scatter(point[0], point[1])
>>> plt.plot([closest_point[0], point[0]], [closest_point[1], point[1]], linestyle="--")
>>> plt.gca().set_aspect("equal")
>>> plt.show()