tensorplay.nn.functional.ctc_loss

tensorplay.nn.functional.ctc_loss(log_probs: TensorBase, targets: TensorBase, input_lengths, target_lengths, blank: int = 0, reduction: str = 'mean', zero_infinity: bool = False) → TensorBase[source]

Compute the Connectionist Temporal Classification loss.

Vectorized dynamic-programming port of aten/src/ATen/native/LossCTC.cpp (alpha recurrence over the blank-extended target sequence); autograd flows through log_probs via the composed primitives.

Parameters:

• log_probs – \((T, N, C)\) or \((T, C)\) log-softmax outputs.

• targets – \((N, S)\) or concatenated \((\sum S_n,)\).

• target_lengths (input_lengths /) – \((N,)\) or scalars.

• blank – index of the blank label. Default: 0.

• reduction – 'none' | 'mean' | 'sum'.

• zero_infinity – zero out infinite losses (targets too long for T).