# diagflat¶

paddle. diagflat ( x, offset=0, name=None ) [source]

If `x` is a vector (1-D tensor), a 2-D square tensor with the elements of `x` as the diagonal is returned.

If `x` is a tensor (more than 1-D), a 2-D square tensor with the elements of flattened `x` as the diagonal is returned.

The argument `offset` controls the diagonal offset.

If `offset` = 0, it is the main diagonal.

If `offset` > 0, it is superdiagonal.

If `offset` < 0, it is subdiagonal.

Parameters
• x (Tensor) – The input tensor. It can be any shape. Its data type should be float16, float32, float64, int32, int64.

• offset (int, optional) – The diagonal offset. A positive value represents superdiagonal, 0 represents the main diagonal, and a negative value represents subdiagonal. Default: 0 (main diagonal).

• name (str, optional) – For details, please refer to Name. Generally, no setting is required. Default: None.

Returns

Tensor, a square matrix. The output data type is the same as input data type.

Examples

```>>> import paddle

>>> x = paddle.to_tensor([1, 2, 3])
>>> print(y)
[[1, 0, 0],
[0, 2, 0],
[0, 0, 3]])

>>> print(y)
[[0, 1, 0, 0],
[0, 0, 2, 0],
[0, 0, 0, 3],
[0, 0, 0, 0]])

>>> print(y)
[[0, 0, 0, 0],
[1, 0, 0, 0],
[0, 2, 0, 0],
[0, 0, 3, 0]])
```
```>>> import paddle

>>> x = paddle.to_tensor([[1, 2], [3, 4]])
>>> print(y)
[[1, 0, 0, 0],
[0, 2, 0, 0],
[0, 0, 3, 0],
[0, 0, 0, 4]])

>>> print(y)
[[0, 1, 0, 0, 0],
[0, 0, 2, 0, 0],
[0, 0, 0, 3, 0],
[0, 0, 0, 0, 4],
[0, 0, 0, 0, 0]])