backward

backward(heads, head_grads=None, retain_graph=False, train_mode=True)

Compute the gradients of heads w.r.t previously marked variables.

Parameters:

heads: NDArray or list of NDArray

Output NDArray(s)

head_grads: NDArray or list of NDArray or None

Gradients with respect to heads.

train_mode: bool, optional

Whether to do backward for training or predicting.