scipy.signal.quadratic

scipy.signal.quadratic(x)

Deprecated since version 1.11.0: scipy.signal.quadratic is deprecated in SciPy 1.11 and will be removed in SciPy 1.13.

The exact equivalent (for a float array x) is:

>>> from scipy.interpolate import BSpline
>>> out = BSpline.basis_element([-1.5, -0.5, 0.5, 1.5])(x)
>>> out[(x < -1.5 | (x > 1.5)] = 0.0

A quadratic B-spline.

This is a special case of bspline, and equivalent to bspline(x, 2).

Parameters:

xarray_like

a knot vector

Returns:

resndarray

Quadratic B-spline basis function values

See also

bspline

B-spline basis function of order n

cubic

A cubic B-spline.

Examples

We can calculate B-Spline basis function of several orders:

>>> import numpy as np
>>> from scipy.signal import bspline, cubic, quadratic
>>> bspline(0.0, 1)
1

>>> knots = [-1.0, 0.0, -1.0]
>>> bspline(knots, 2)
array([0.125, 0.75, 0.125])

>>> np.array_equal(bspline(knots, 2), quadratic(knots))
True

>>> np.array_equal(bspline(knots, 3), cubic(knots))
True