# scipy.interpolate.InterpolatedUnivariateSpline.integral¶

InterpolatedUnivariateSpline.integral(a, b)[source]

Return definite integral of the spline between two given points.

Parameters: a : float Lower limit of integration. b : float Upper limit of integration. integral : float The value of the definite integral of the spline between limits.

Examples

>>> from scipy.interpolate import UnivariateSpline
>>> x = np.linspace(0, 3, 11)
>>> y = x**2
>>> spl = UnivariateSpline(x, y)
>>> spl.integral(0, 3)
9.0


which agrees with $$\int x^2 dx = x^3 / 3$$ between the limits of 0 and 3.

A caveat is that this routine assumes the spline to be zero outside of the data limits:

>>> spl.integral(-1, 4)
9.0
>>> spl.integral(-1, 0)
0.0