nnf_log_softmax function

Log_softmax

Applies a softmax followed by a logarithm.

nnf_log_softmax(input, dim = NULL, dtype = NULL)

Arguments

• 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 casted to dtype before the operation is performed. This is useful for preventing data type overflows. Default: NULL.

Details

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.