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scipy.integrate.

# simpson

scipy.integrate.simpson(y, x=None, *, dx=1.0, axis=-1)

  Integrate y(x) using samples along the given axis and the composite Simpson’s rule. If x is None, spacing of dx is assumed.

  Parameters:
    yarray_like

      Array to be integrated.

    xarray_like, optional

      If given, the points at which y is sampled.

    dxfloat, optional

      Spacing of integration points along axis of x. Only used when x is None. Default is 1.

    axisint, optional

      Axis along which to integrate. Default is the last axis.

  Returns:
    float

      The estimated integral computed with the composite Simpson’s rule.

  See also

  `quad`

    adaptive quadrature using QUADPACK

  `fixed_quad`

    fixed-order Gaussian quadrature

  `dblquad`

    double integrals

  `tplquad`

    triple integrals

  `romb`

    integrators for sampled data

  `cumulative_trapezoid`

    cumulative integration for sampled data

  `cumulative_simpson`

    cumulative integration using Simpson’s 1/3 rule

  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.

  References

  [1]

  Cartwright, Kenneth V. Simpson’s Rule Cumulative Integration with MS Excel and Irregularly-spaced Data. Journal of Mathematical Sciences and Mathematics Education. 12 (2): 1-9

  Examples

      >>> from scipy import integrate
      >>> import numpy as np
      >>> x = np.arange(0, 10)
      >>> y = np.arange(0, 10)

      >>> integrate.simpson(y, x=x)
      40.5

      >>> y = np.power(x, 3)
      >>> integrate.simpson(y, x=x)
      1640.5
      >>> integrate.quad(lambda x: x**3, 0, 9)[0]
      1640.25