# LogSoftmax¶

class paddle.nn. LogSoftmax ( axis=- 1, name=None ) [source]

This operator implements the log_softmax layer. The calculation process is as follows:

$\begin{split}\begin{array} {rcl} Out[i, j] &= &log(softmax(x)) \\ &= &log(\frac{\exp(X[i, j])}{\sum_j(\exp(X[i, j])}) \end{array}\end{split}$
Parameters
• axis (int, optional) – The axis along which to perform log_softmax calculations. It should be in range [-D, D), where D is the dimensions of the input Tensor . If axis < 0, it works the same way as $$axis + D$$ . Default is -1.

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

Shape:
• input: Tensor with any shape.

• output: Tensor with the same shape as input.

Examples

import paddle

x = [[[-2.0, 3.0, -4.0, 5.0],
[3.0, -4.0, 5.0, -6.0],
[-7.0, -8.0, 8.0, 9.0]],
[[1.0, -2.0, -3.0, 4.0],
[-5.0, 6.0, 7.0, -8.0],
[6.0, 7.0, 8.0, 9.0]]]
out = m(x)
# [[[ -7.1278396   -2.1278396   -9.127839    -0.12783948]
#   [ -2.1270514   -9.127051    -0.12705144 -11.127051  ]
#   [-16.313261   -17.313261    -1.3132617   -0.31326184]]
#  [[ -3.0518122   -6.051812    -7.051812    -0.051812  ]
#   [-12.313267    -1.3132664   -0.3132665  -15.313267  ]
#   [ -3.4401896   -2.4401896   -1.4401896   -0.44018966]]]

forward ( x )

Defines the computation performed at every call. Should be overridden by all subclasses.

Parameters
• *inputs (tuple) – unpacked tuple arguments

• **kwargs (dict) – unpacked dict arguments

extra_repr ( )

Extra representation of this layer, you can have custom implementation of your own layer.