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 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) – Name for the operation (optional, default is None). For more information, please refer to Name.

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])
y = paddle.diagflat(x)
print(y.numpy())
# [[1 0 0]
#  [0 2 0]
#  [0 0 3]]

y = paddle.diagflat(x, offset=1)
print(y.numpy())
# [[0 1 0 0]
#  [0 0 2 0]
#  [0 0 0 3]
#  [0 0 0 0]]

y = paddle.diagflat(x, offset=-1)
print(y.numpy())
# [[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]])
y = paddle.diagflat(x)
print(y.numpy())
# [[1 0 0 0]
#  [0 2 0 0]
#  [0 0 3 0]
#  [0 0 0 4]]

y = paddle.diagflat(x, offset=1)
print(y.numpy())
# [[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]]

y = paddle.diagflat(x, offset=-1)
print(y.numpy())
# [[0 0 0 0 0]
#  [1 0 0 0 0]
#  [0 2 0 0 0]
#  [0 0 3 0 0]
#  [0 0 0 4 0]]