MatrixSetDiag

output[i, j, ..., l, m, n]
   = diagonal[i, j, ..., l, n-max(k[1], 0)] ; if n - m == k[1]
     input[i, j, ..., l, m, n]              ; otherwise
 

output[i, j, ..., l, m, n]
   = diagonal[i, j, ..., l, diag_index, index_in_diag] ; if k[0] <= d <= k[1]
     input[i, j, ..., l, m, n]                         ; otherwise
 

offset = max_diag_len - diag_len(d) ; if (`align` in {RIGHT_LEFT, RIGHT_RIGHT
                                            and `d >= 0`) or
                                          (`align` in {LEFT_RIGHT, RIGHT_RIGHT}
                                            and `d <= 0`)
          0                          ; otherwise
 }

# The main diagonal.
 input = np.array([[[7, 7, 7, 7],              # Input shape: (2, 3, 4)
                    [7, 7, 7, 7],
                    [7, 7, 7, 7]],
                   [[7, 7, 7, 7],
                    [7, 7, 7, 7],
                    [7, 7, 7, 7]]])
 diagonal = np.array([[1, 2, 3],               # Diagonal shape: (2, 3)
                      [4, 5, 6]])
 tf.matrix_set_diag(input, diagonal)
   ==> [[[1, 7, 7, 7],  # Output shape: (2, 3, 4)
         [7, 2, 7, 7],
         [7, 7, 3, 7]],
        [[4, 7, 7, 7],
         [7, 5, 7, 7],
         [7, 7, 6, 7]]]
 
 # A superdiagonal (per batch).
 tf.matrix_set_diag(input, diagonal, k = 1)
   ==> [[[7, 1, 7, 7],  # Output shape: (2, 3, 4)
         [7, 7, 2, 7],
         [7, 7, 7, 3]],
        [[7, 4, 7, 7],
         [7, 7, 5, 7],
         [7, 7, 7, 6]]]
 
 # A band of diagonals.
 diagonals = np.array([[[0, 9, 1],  # Diagonal shape: (2, 4, 3)
                        [6, 5, 8],
                        [1, 2, 3],
                        [4, 5, 0]],
                       [[0, 1, 2],
                        [5, 6, 4],
                        [6, 1, 2],
                        [3, 4, 0]]])
 tf.matrix_set_diag(input, diagonals, k = (-1, 2))
   ==> [[[1, 6, 9, 7],  # Output shape: (2, 3, 4)
         [4, 2, 5, 1],
         [7, 5, 3, 8]],
        [[6, 5, 1, 7],
         [3, 1, 6, 2],
         [7, 4, 2, 4]]]
 
 # LEFT_RIGHT alignment.
 diagonals = np.array([[[9, 1, 0],  # Diagonal shape: (2, 4, 3)
                        [6, 5, 8],
                        [1, 2, 3],
                        [0, 4, 5]],
                       [[1, 2, 0],
                        [5, 6, 4],
                        [6, 1, 2],
                        [0, 3, 4]]])
 tf.matrix_set_diag(input, diagonals, k = (-1, 2), align="LEFT_RIGHT")
   ==> [[[1, 6, 9, 7],  # Output shape: (2, 3, 4)
         [4, 2, 5, 1],
         [7, 5, 3, 8]],
        [[6, 5, 1, 7],
         [3, 1, 6, 2],
         [7, 4, 2, 4]]]