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# numpy.diagflat

`numpy.``diagflat`(v, k=0)

  Create a two-dimensional array with the flattened input as a diagonal.

  Parameters : | v : array_like Input data, which is flattened and set as the k-th diagonal of the output. k : int, optional Diagonal to set; 0, the default, corresponds to the “main” diagonal, a positive (negative) k giving the number of the diagonal above (below) the main.
  Returns : | out : ndarray The 2-D output array.

  See also

  `diag`
    MATLAB work-alike for 1-D and 2-D arrays.
  `diagonal`
    Return specified diagonals.
  `trace`
    Sum along diagonals.

  Examples

      >>> np.diagflat([[1,2], [3,4]])
      array([[1, 0, 0, 0],
             [0, 2, 0, 0],
             [0, 0, 3, 0],
             [0, 0, 0, 4]])

      >>> np.diagflat([1,2], 1)
      array([[0, 1, 0],
             [0, 0, 2],
             [0, 0, 0]])