torchrl.objectives.symexp

torchrl.objectives.symexp(x: Tensor) → Tensor

Symmetric exponential: sign(x) * (exp(|x|) - 1).

Inverse of symlog().

Reference: https://arxiv.org/abs/2301.04104

Parameters:

x – Input tensor.

Returns:

Tensor of the same shape as x.

Examples

>>> import torch
>>> from torchrl.objectives import symexp, symlog
>>> x = torch.tensor([-1000.0, -1.0, 0.0, 1.0, 1000.0])
>>> torch.allclose(symexp(symlog(x)), x, atol=1e-4)
True