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 (N1), but Simpson’s rule requires an even number of intervals. The parameter ‘even’ controls how this is handled.
Parameters :  y : array_like
x : array_like, optional
dx : int, optional
axis : int, optional
even : {‘avg’, ‘first’, ‘str’}, optional


See also
Notes
For an odd number of samples that are equally spaced the result is exact if the function is a polynomial of order 3 or less. If the samples are not equally spaced, then the result is exact only if the function is a polynomial of order 2 or less.