Logsumexp
Source:R/gen-namespace-docs.R
, R/gen-namespace-examples.R
, R/gen-namespace.R
torch_logsumexp.Rd
Logsumexp
Arguments
- self
(Tensor) the input tensor.
- dim
(int or tuple of ints) the dimension or dimensions to reduce.
- keepdim
(bool) whether the output tensor has
dim
retained or not.
logsumexp(input, dim, keepdim=False, out=NULL)
Returns the log of summed exponentials of each row of the input
tensor in the given dimension dim
. The computation is numerically
stabilized.
For summation index \(j\) given by dim
and other indices \(i\), the result is
$$ \mbox{logsumexp}(x)_{i} = \log \sum_j \exp(x_{ij}) $$
If keepdim
is TRUE
, the output tensor is of the same size
as input
except in the dimension(s) dim
where it is of size 1.
Otherwise, dim
is squeezed (see torch_squeeze
), resulting in the
output tensor having 1 (or len(dim)
) fewer dimension(s).
Examples
if (torch_is_installed()) {
a = torch_randn(c(3, 3))
torch_logsumexp(a, 1)
}
#> torch_tensor
#> 1.8542
#> 1.3111
#> 2.1658
#> [ CPUFloatType{3} ]