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| ``mx.nd.diag`` |
| ============================ |
| |
| Description |
| ---------------------- |
| |
| Extracts a diagonal or constructs a diagonal array. |
| |
| ``diag``'s behavior depends on the input array dimensions: |
| |
| - 1-D arrays: constructs a 2-D array with the input as its diagonal, all other elements are zero. |
| - N-D arrays: extracts the diagonals of the sub-arrays with axes specified by ``axis1`` and ``axis2``. |
| The output shape would be decided by removing the axes numbered ``axis1`` and ``axis2`` from the |
| input shape and appending to the result a new axis with the size of the diagonals in question. |
| |
| For example, when the input shape is `(2, 3, 4, 5)`, ``axis1`` and ``axis2`` are 0 and 2 |
| respectively and ``k`` is 0, the resulting shape would be `(3, 5, 2)`. |
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| **Example**:: |
| |
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| x = [[1, 2, 3], |
| [4, 5, 6]] |
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| diag(x) = [1, 5] |
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| diag(x, k=1) = [2, 6] |
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| diag(x, k=-1) = [4] |
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| x = [1, 2, 3] |
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| diag(x) = [[1, 0, 0], |
| [0, 2, 0], |
| [0, 0, 3]] |
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| diag(x, k=1) = [[0, 1, 0], |
| [0, 0, 2], |
| [0, 0, 0]] |
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| diag(x, k=-1) = [[0, 0, 0], |
| [1, 0, 0], |
| [0, 2, 0]] |
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| x = [[[1, 2], |
| [3, 4]], |
| |
| [[5, 6], |
| [7, 8]]] |
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| diag(x) = [[1, 7], |
| [2, 8]] |
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| diag(x, k=1) = [[3], |
| [4]] |
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| diag(x, axis1=-2, axis2=-1) = [[1, 4], |
| [5, 8]] |
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| Arguments |
| ------------------ |
| |
| +----------------------------------------+------------------------------------------------------------+ |
| | Argument | Description | |
| +========================================+============================================================+ |
| | ``data`` | NDArray-or-Symbol. | |
| | | | |
| | | Input ndarray | |
| +----------------------------------------+------------------------------------------------------------+ |
| | ``k`` | int, optional, default='0'. | |
| | | | |
| | | Diagonal in question. The default is 0. Use k>0 for | |
| | | diagonals above the main diagonal, and k<0 for diagonals | |
| | | below the main diagonal. If input has shape (S0 S1) k must | |
| | | be between -S0 and | |
| | | S1 | |
| +----------------------------------------+------------------------------------------------------------+ |
| | ``axis1`` | int, optional, default='0'. | |
| | | | |
| | | The first axis of the sub-arrays of interest. Ignored when | |
| | | the input is a 1-D | |
| | | array. | |
| +----------------------------------------+------------------------------------------------------------+ |
| | ``axis2`` | int, optional, default='1'. | |
| | | | |
| | | The second axis of the sub-arrays of interest. Ignored | |
| | | when the input is a 1-D | |
| | | array. | |
| +----------------------------------------+------------------------------------------------------------+ |
| |
| Value |
| ---------- |
| |
| ``out`` The result mx.ndarray |
| |
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| Link to Source Code: http://github.com/apache/incubator-mxnet/blob/1.6.0/src/operator/tensor/diag_op.cc#L87 |
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