qrisp.QuantumArray.init_from

QuantumArray.init_from(other)

Performs the init_from method on all containing QuantumVariables based on their equivalent in the QuantumArray other. Note that this method does not copy the quantum state. For more details check the documentation of the init_from method of QuantumVariable.

A shorthand for this method is the slicing operator [:].

Parameters

otherQuantumArray

The QuantumArray from which to initiate.

Raises

Exception

Tried to initialize from array of invalied shape or qtype.

Examples

We create a QuantumArray and bring it into superposition

>>> import numpy as np
>>> from qrisp import QuantumArray, QuantumFloat, h, multi_measurement
>>> qtype = QuantumFloat(5)
>>> q_array_a = QuantumArray(qtype)
>>> q_array_a[:] = np.eye(3)
>>> h(q_array_a[0,0][0])
>>> print(q_array_a)
{OutcomeArray([[0, 0, 0],
               [0, 1, 0],
               [0, 0, 1]]): 0.5,
 OutcomeArray([[1, 0, 0],
               [0, 1, 0],
               [0, 0, 1]]): 0.5}

We now duplicate this array and initiate

>>> q_array_b = q_array_a.duplicate()
>>> q_array_b.init_from(q_array_a)
>>> print(multi_measurement([q_array_a, q_array_b]))
        {(OutcomeArray([[0, 0, 0],
                        [0, 1, 0],
                        [0, 0, 1]]),
          OutcomeArray([[0, 0, 0],
                        [0, 1, 0],
                        [0, 0, 1]])): 0.5,
         (OutcomeArray([[1, 0, 0],
                        [0, 1, 0],
                        [0, 0, 1]]),
          OutcomeArray([[1, 0, 0],
                        [0, 1, 0],
                        [0, 0, 1]])): 0.5}

We can achieve the same with the slicing operator

>>> q_array_c = QuantumArray(qtype, shape = (3, 3))
>>> q_array_c[1,:] = q_array_a[0,:]
>>> print(multi_measurement([q_array_b, q_array_c]))
{(OutcomeArray([[0, 0, 0],
                [0, 0, 0],
                [0, 0, 0]]),
  OutcomeArray([[0, 0, 0],
                [0, 0, 0],
                [0, 0, 0]])): 0.5,
 (OutcomeArray([[0, 0, 0],
                [1, 0, 0],
                [0, 0, 0]]),
  OutcomeArray([[0, 0, 0],
                [1, 0, 0],
                [0, 0, 0]])): 0.5}