torch.nn.functional.log_softmax¶
-
torch.nn.functional.
log_softmax
(input, dim=None, _stacklevel=3, dtype=None)[source]¶ Applies a softmax followed by a logarithm.
While mathematically equivalent to log(softmax(x)), doing these two operations separately is slower and numerically unstable. This function uses an alternative formulation to compute the output and gradient correctly.
See
LogSoftmax
for more details.- Parameters
input (Tensor) – input
dim (int) – A dimension along which log_softmax will be computed.
dtype (
torch.dtype
, optional) – the desired data type of returned tensor. If specified, the input tensor is cast todtype
before the operation is performed. This is useful for preventing data type overflows. Default: None.