diag_embed

paddle.nn.functional. diag_embed ( input, offset=0, dim1=- 2, dim2=- 1 ) [source]

This OP creates a tensor whose diagonals of certain 2D planes (specified by dim1 and dim2) are filled by input. By default, a 2D plane formed by the last two dimensions of the returned tensor will be selected.

The argument offset determines which diagonal is generated:

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

  • If offset > 0, it is above the main diagonal.

  • If offset < 0, it is below the main diagonal.

Parameters
  • input (Tensor|numpy.ndarray) – The input tensor. Must be at least 1-dimensional. The input data type should be float32, float64, int32, int64.

  • offset (int, optional) – Which diagonal to consider. Default: 0 (main diagonal).

  • dim1 (int, optional) – The first dimension with respect to which to take diagonal. Default: -2.

  • dim2 (int, optional) – The second dimension with respect to which to take diagonal. Default: -1.

Returns

Tensor, the output data type is the same as input data type.

Examples

import paddle.nn.functional as F
import numpy as np

diag_embed = np.random.randn(2, 3).astype('float32')
# [[ 0.7545889 , -0.25074545,  0.5929117 ],
#  [-0.6097662 , -0.01753256,  0.619769  ]]

data1 = F.diag_embed(diag_embed)
data1.numpy()
# [[[ 0.7545889 ,  0.        ,  0.        ],
#  [ 0.        , -0.25074545,  0.        ],
#   [ 0.        ,  0.        ,  0.5929117 ]],

# [[-0.6097662 ,  0.        ,  0.        ],
#  [ 0.        , -0.01753256,  0.        ],
#  [ 0.        ,  0.        ,  0.619769  ]]]

data2 = F.diag_embed(diag_embed, offset=-1, dim1=0, dim2=2)
data2.numpy()
# [[[ 0.        ,  0.        ,  0.        ,  0.        ],
#   [ 0.7545889 ,  0.        ,  0.        ,  0.        ],
#   [ 0.        , -0.25074545,  0.        ,  0.        ],
#   [ 0.        ,  0.        ,  0.5929117 ,  0.        ]],
#
#  [[ 0.        ,  0.        ,  0.        ,  0.        ],
#   [-0.6097662 ,  0.        ,  0.        ,  0.        ],
#   [ 0.        , -0.01753256,  0.        ,  0.        ],
#   [ 0.        ,  0.        ,  0.619769  ,  0.        ]]]

data3 = F.diag_embed(diag_embed, offset=1, dim1=0, dim2=2)
data3.numpy()
# [[[ 0.        ,  0.7545889 ,  0.        ,  0.        ],
#   [ 0.        , -0.6097662 ,  0.        ,  0.        ]],
#
#  [[ 0.        ,  0.        , -0.25074545,  0.        ],
#   [ 0.        ,  0.        , -0.01753256,  0.        ]],
#
#  [[ 0.        ,  0.        ,  0.        ,  0.5929117 ],
#   [ 0.        ,  0.        ,  0.        ,  0.619769  ]],
#
#  [[ 0.        ,  0.        ,  0.        ,  0.        ],
#   [ 0.        ,  0.        ,  0.        ,  0.        ]]]