Вы можете использовать правило Симпсона. Обычная процедура, которая делает это для вас, - simps
в spicy.integrate
.
>>> help(scipy.integrate.simps)
Help on function simps in module scipy.integrate.quadrature:
simps(y, x=None, dx=1, axis=-1, even='avg')
Integrate y(x) using samples along the given axis and the composite
Simpson's rule. If x is None, spacing of dx is assumed.
If there are an even number of samples, N, then there are an odd
number of intervals (N-1), but Simpson's rule requires an even number
of intervals. The parameter 'even' controls how this is handled.