qml.math.get_trainable_indices¶
-
get_trainable_indices
(values, like=None)[source]¶ Returns a set containing the trainable indices of a sequence of values.
- Parameters
values (Iterable[tensor_like]) – Sequence of tensor-like objects to inspect
- Returns
Set containing the indices of the trainable tensor-like objects within the input sequence.
- Return type
set[int]
Example
>>> from pennylane import numpy as pnp >>> def cost_fn(params): ... print("Trainable:", qml.math.get_trainable_indices(params)) ... return np.sum(np.sin(params[0] * params[1])) >>> values = [pnp.array([0.1, 0.2], requires_grad=True), ... pnp.array([0.5, 0.2], requires_grad=False)] >>> cost_fn(values) Trainable: {0} tensor(0.0899685, requires_grad=True)
code/api/pennylane.math.get_trainable_indices
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