# qiskit.providers.aer.library.SaveAmplitudes¶

class SaveAmplitudes(num_qubits, params, label='amplitudes', pershot=False, conditional=False)[source]

Save complex statevector amplitudes.

Instruction to save complex statevector amplitudes.

Parameters
• num_qubits (int) – the number of qubits for the snapshot type.

• params (list) – list of entries to vale.

• label (str) – the key for retrieving saved data from results.

• pershot (bool) – if True save a list of amplitudes vectors for each shot of the simulation rather than the a single amplitude vector [Default: False].

• conditional (bool) – if True save the amplitudes vector conditional on the current classical register values [Default: False].

Raises

ExtensionError – if params is invalid for the specified number of qubits.

__init__(num_qubits, params, label='amplitudes', pershot=False, conditional=False)[source]

Instruction to save complex statevector amplitudes.

Parameters
• num_qubits (int) – the number of qubits for the snapshot type.

• params (list) – list of entries to vale.

• label (str) – the key for retrieving saved data from results.

• pershot (bool) – if True save a list of amplitudes vectors for each shot of the simulation rather than the a single amplitude vector [Default: False].

• conditional (bool) – if True save the amplitudes vector conditional on the current classical register values [Default: False].

Raises

ExtensionError – if params is invalid for the specified number of qubits.

Methods

 __init__(num_qubits, params[, label, …]) Instruction to save complex statevector amplitudes. add_decomposition(decomposition) Add a decomposition of the instruction to the SessionEquivalenceLibrary. Return the QasmQobjInstruction for the intructions. 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. Special case. 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. soft_compare(other) Soft comparison between gates. validate_parameter(parameter) Instruction parameters has no validation or normalization.

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()

Return the QasmQobjInstruction for the intructions.

broadcast_arguments(qargs, cargs)

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.

inverse()

Special case. Return self.

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

soft_compare(other)

Soft comparison between gates. Their names, number of qubits, and classical bit numbers must match. The number of parameters must match. Each parameter is compared. If one is a ParameterExpression then it is not taken into account.

Parameters

other (instruction) – other instruction.

Returns

are self and other equal up to parameter expressions.

Return type

bool

property unit

Get the time unit of duration.

validate_parameter(parameter)

Instruction parameters has no validation or normalization.