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cirq.linalg.transformations.factor_state_vector

Factors a state vector into two independent state vectors.

cirq.linalg.transformations.factor_state_vector(
    t: np.ndarray, axes: Sequence[int], *, validate=True, atol=1e-07
) -> Tuple[np.ndarray, np.ndarray]

This function should only be called on state vectors that are known to be separable, such as immediately after a measurement or reset operation. It does not verify that the provided state vector is indeed separable, and will return nonsense results for vectors representing entangled states.

t The state vector to factor.
axes The axes to factor out.
validate Perform a validation that the density matrix factors cleanly.
atol The absolute tolerance for the validation.

A tuple with the (extracted, remainder) state vectors, where extracted means the sub-state vector which corresponds to the axes requested, and with the axes in the requested order, and where remainder means the sub-state vector on the remaining axes, in the same order as the original state vector.

EntangledStateError If the tensor is already in entangled state, and the validate flag is set.
ValueError If the tensor factorization fails for any other reason.