#### Previous topic

numpy.cumsum

#### Next topic

numpy.ediff1d

# numpy.diff

`numpy.``diff`(a, n=1, axis=-1)

  > Calculate the n-th discrete difference along given axis.

  > The first difference is given by `out[n] = a[n+1] - a[n]` along the given axis, higher differences are calculated by using `diff` recursively.

  Parameters: | a : array_like Input array n : int, optional The number of times values are differenced. axis : int, optional The axis along which the difference is taken, default is the last axis.
  Returns: | diff : ndarray The n-th differences. The shape of the output is the same as a except along axis where the dimension is smaller by n. .

  Examples

      >>> x = np.array([1, 2, 4, 7, 0])
      >>> np.diff(x)
      array([ 1,  2,  3, -7])
      >>> np.diff(x, n=2)
      array([  1,   1, -10])

      >>> x = np.array([[1, 3, 6, 10], [0, 5, 6, 8]])
      >>> np.diff(x)
      array([[2, 3, 4],
             [5, 1, 2]])
      >>> np.diff(x, axis=0)
      array([[-1,  2,  0, -2]])