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# numpy.ediff1d

numpy.ediff1d(ary, to_end=None, to_begin=None)

  The differences between consecutive elements of an array.

  Parameters:
    ary array_like

      If necessary, will be flattened before the differences are taken.

    to_end array_like, optional

      Number(s) to append at the end of the returned differences.

    to_begin array_like, optional

      Number(s) to prepend at the beginning of the returned differences.

  Returns:
    ediff1d ndarray

      The differences. Loosely, this is `ary.flat[1:] - ary.flat[:-1]`.

  See also

  `diff`, `gradient`

  Notes

  When applied to masked arrays, this function drops the mask information if the to_begin and/or to_end parameters are used.

  Examples

      >>> import numpy as np
      >>> x = np.array([1, 2, 4, 7, 0])
      >>> np.ediff1d(x)
      array([ 1,  2,  3, -7])

      >>> np.ediff1d(x, to_begin=-99, to_end=np.array([88, 99]))
      array([-99,   1,   2, ...,  -7,  88,  99])

  The returned array is always 1D.

      >>> y = [[1, 2, 4], [1, 6, 24]]
      >>> np.ediff1d(y)
      array([ 1,  2, -3,  5, 18])