# qiskit.extensions.Initialize¶

class Initialize(params)[source]

Complex amplitude initialization.

Class that implements the (complex amplitude) initialization of some flexible collection of qubit registers (assuming the qubits are in the zero state). Note that Initialize is an Instruction and not a Gate since it contains a reset instruction, which is not unitary.

Create new initialize composite.

params (list): vector of complex amplitudes to initialize to

__init__(params)[source]

Create new initialize composite.

params (list): vector of complex amplitudes to initialize to

Methods

 __init__(params) Create new initialize composite. add_decomposition(decomposition) Add a decomposition of the instruction to the SessionEquivalenceLibrary. Assemble a QasmQobjInstruction broadcast_arguments(qargs, cargs) Validation of the arguments. c_if(classical, val) Add classical condition on register classical and value val. copy([name]) Copy of the instruction. Call to create a circuit with gates that take the desired vector to zero. Invert this instruction. Return True .IFF. DEPRECATED: use instruction.reverse_ops(). Return a default OpenQASM string for the instruction. Creates an instruction with gate repeated n amount of times. For a composite instruction, reverse the order of sub-instructions. validate_parameter(parameter) Initialize instruction parameter can be int, float, and complex.

Attributes

 decompositions Get the decompositions of the instruction from the SessionEquivalenceLibrary. definition Return definition in terms of other basic gates. duration Get the duration. params return instruction params. unit Get the time unit of duration.
add_decomposition(decomposition)

Add a decomposition of the instruction to the SessionEquivalenceLibrary.

assemble()

Assemble a QasmQobjInstruction

broadcast_arguments(qargs, cargs)[source]

Validation of the arguments.

Parameters
• qargs (List) – List of quantum bit arguments.

• cargs (List) – List of classical bit arguments.

Yields

Tuple(List, List) – A tuple with single arguments.

Raises

CircuitError – If the input is not valid. For example, the number of arguments does not match the gate expectation.

c_if(classical, val)

Add classical condition on register classical and value val.

copy(name=None)

Copy of the instruction.

Parameters

name (str) – name to be given to the copied circuit, if None then the name stays the same.

Returns

a copy of the current instruction, with the name

updated if it was provided

Return type

qiskit.circuit.Instruction

property decompositions

Get the decompositions of the instruction from the SessionEquivalenceLibrary.

property definition

Return definition in terms of other basic gates.

property duration

Get the duration.

gates_to_uncompute()[source]

Call to create a circuit with gates that take the desired vector to zero.

Returns

circuit to take self.params vector to $$|{00\ldots0}\rangle$$

Return type

QuantumCircuit

inverse()

Invert this instruction.

If the instruction is composite (i.e. has a definition), then its definition will be recursively inverted.

Special instructions inheriting from Instruction can implement their own inverse (e.g. T and Tdg, Barrier, etc.)

Returns

a fresh instruction for the inverse

Return type

qiskit.circuit.Instruction

Raises

CircuitError – if the instruction is not composite and an inverse has not been implemented for it.

is_parameterized()

Return True .IFF. instruction is parameterized else False

mirror()

DEPRECATED: use instruction.reverse_ops().

Returns

a new instruction with sub-instructions

reversed.

Return type

qiskit.circuit.Instruction

property params

return instruction params.

qasm()

Return a default OpenQASM string for the instruction.

Derived instructions may override this to print in a different format (e.g. measure q[0] -> c[0];).

repeat(n)

Creates an instruction with gate repeated n amount of times.

Parameters

n (int) – Number of times to repeat the instruction

Returns

Containing the definition.

Return type

qiskit.circuit.Instruction

Raises

CircuitError – If n < 1.

reverse_ops()

For a composite instruction, reverse the order of sub-instructions.

This is done by recursively reversing all sub-instructions. It does not invert any gate.

Returns

a new instruction with

sub-instructions reversed.

Return type

qiskit.circuit.Instruction

property unit

Get the time unit of duration.

validate_parameter(parameter)[source]

Initialize instruction parameter can be int, float, and complex.