MatrixDiagPartV3

public final class MatrixDiagPartV3

Returns the batched diagonal part of a batched tensor.

Returns a tensor with the `k[0]`-th to `k[1]`-th diagonals of the batched `input`.

Assume `input` has `r` dimensions `[I, J, ..., L, M, N]`. Let `max_diag_len` be the maximum length among all diagonals to be extracted, `max_diag_len = min(M + min(k[1], 0), N + min(-k[0], 0))` Let `num_diags` be the number of diagonals to extract, `num_diags = k[1] - k[0] + 1`.

If `num_diags == 1`, the output tensor is of rank `r - 1` with shape `[I, J, ..., L, max_diag_len]` and values:

diagonal[i, j, ..., l, n]
   = input[i, j, ..., l, n+y, n+x] ; if 0 <= n+y < M and 0 <= n+x < N,
     padding_value                 ; otherwise.
 
where `y = max(-k[1], 0)`, `x = max(k[1], 0)`.

Otherwise, the output tensor has rank `r` with dimensions `[I, J, ..., L, num_diags, max_diag_len]` with values:

diagonal[i, j, ..., l, m, n]
   = input[i, j, ..., l, n+y, n+x] ; if 0 <= n+y < M and 0 <= n+x < N,
     padding_value                 ; otherwise.
 
where `d = k[1] - m`, `y = max(-d, 0) - offset`, and `x = max(d, 0) - offset`.

`offset` is zero except when the alignment of the diagonal is to the right.

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
 }
where `diag_len(d) = min(cols - max(d, 0), rows + min(d, 0))`.

The input must be at least a matrix.

For example:

input = np.array([[[1, 2, 3, 4],  # Input shape: (2, 3, 4)
                    [5, 6, 7, 8],
                    [9, 8, 7, 6]],
                   [[5, 4, 3, 2],
                    [1, 2, 3, 4],
                    [5, 6, 7, 8]]])
 
 # A main diagonal from each batch.
 tf.matrix_diag_part(input) ==> [[1, 6, 7],  # Output shape: (2, 3)
                                 [5, 2, 7]]
 
 # A superdiagonal from each batch.
 tf.matrix_diag_part(input, k = 1)
   ==> [[2, 7, 6],  # Output shape: (2, 3)
        [4, 3, 8]]
 
 # A band from each batch.
 tf.matrix_diag_part(input, k = (-1, 2))
   ==> [[[0, 3, 8],  # Output shape: (2, 4, 3)
         [2, 7, 6],
         [1, 6, 7],
         [5, 8, 0]],
        [[0, 3, 4],
         [4, 3, 8],
         [5, 2, 7],
         [1, 6, 0]]]
 
 # LEFT_RIGHT alignment.
 tf.matrix_diag_part(input, k = (-1, 2), align="LEFT_RIGHT")
   ==> [[[3, 8, 0],  # Output shape: (2, 4, 3)
         [2, 7, 6],
         [1, 6, 7],
         [0, 5, 8]],
        [[3, 4, 0],
         [4, 3, 8],
         [5, 2, 7],
         [0, 1, 6]]]
 
 # max_diag_len can be shorter than the main diagonal.
 tf.matrix_diag_part(input, k = (-2, -1))
   ==> [[[5, 8],
         [9, 0]],
        [[1, 6],
         [5, 0]]]
 
 # padding_value = 9
 tf.matrix_diag_part(input, k = (1, 3), padding_value = 9)
   ==> [[[9, 9, 4],  # Output shape: (2, 3, 3)
         [9, 3, 8],
         [2, 7, 6]],
        [[9, 9, 2],
         [9, 3, 4],
         [4, 3, 8]]]
 
 

Nested Classes

class MatrixDiagPartV3.Options Optional attributes for MatrixDiagPartV3

Constants

String OP_NAME The name of this op, as known by TensorFlow core engine

Public Methods

static MatrixDiagPartV3.Options
align (String align)
Output <T>
asOutput ()
Returns the symbolic handle of the tensor.
static <T extends TType > MatrixDiagPartV3 <T>
create ( Scope scope, Operand <T> input, Operand < TInt32 > k, Operand <T> paddingValue, Options... options)
Factory method to create a class wrapping a new MatrixDiagPartV3 operation.
Output <T>
diagonal ()
The extracted diagonal(s).

Inherited Methods

Constants

public static final String OP_NAME

The name of this op, as known by TensorFlow core engine

Constant Value: "MatrixDiagPartV3"

Public Methods

public static MatrixDiagPartV3.Options align (String align)

Parameters
align Some diagonals are shorter than `max_diag_len` and need to be padded. `align` is a string specifying how superdiagonals and subdiagonals should be aligned, respectively. There are four possible alignments: "RIGHT_LEFT" (default), "LEFT_RIGHT", "LEFT_LEFT", and "RIGHT_RIGHT". "RIGHT_LEFT" aligns superdiagonals to the right (left-pads the row) and subdiagonals to the left (right-pads the row). It is the packing format LAPACK uses. cuSPARSE uses "LEFT_RIGHT", which is the opposite alignment.

public Output <T> asOutput ()

Returns the symbolic handle of the tensor.

Inputs to TensorFlow operations are outputs of another TensorFlow operation. This method is used to obtain a symbolic handle that represents the computation of the input.

public static MatrixDiagPartV3 <T> create ( Scope scope, Operand <T> input, Operand < TInt32 > k, Operand <T> paddingValue, Options... options)

Factory method to create a class wrapping a new MatrixDiagPartV3 operation.

Parameters
scope current scope
input Rank `r` tensor where `r >= 2`.
k Diagonal offset(s). Positive value means superdiagonal, 0 refers to the main diagonal, and negative value means subdiagonals. `k` can be a single integer (for a single diagonal) or a pair of integers specifying the low and high ends of a matrix band. `k[0]` must not be larger than `k[1]`.
paddingValue The value to fill the area outside the specified diagonal band with. Default is 0.
options carries optional attributes values
Returns
  • a new instance of MatrixDiagPartV3

public Output <T> diagonal ()

The extracted diagonal(s).