# qiskit.quantum_info.DensityMatrix.from_instruction¶

classmethod DensityMatrix.from_instruction(instruction)[source]

Return the output density matrix of an instruction.

The statevector is initialized in the state $$|{0,\ldots,0}\rangle$$ of the same number of qubits as the input instruction or circuit, evolved by the input instruction, and the output statevector returned.

Parameters

instruction (qiskit.circuit.Instruction or QuantumCircuit) – instruction or circuit

Returns

the final density matrix.

Return type

DensityMatrix

Raises

QiskitError – if the instruction contains invalid instructions for density matrix simulation.