qiskit.visualization.plot_state_city

plot_state_city(state, title='', figsize=None, color=None, alpha=1, ax_real=None, ax_imag=None, *, rho=None, filename=None)

Plot the cityscape of quantum state.

Plot two 3d bar graphs (two dimensional) of the real and imaginary part of the density matrix rho.

バージョン 0.15.1 で非推奨: qiskit.visualization.state_visualization.plot_state_city()』s argument rho is deprecated as of qiskit-terra 0.15.1. It will be removed no earlier than 3 months after the release date. Instead, use the argument state, which behaves identically.

パラメータ

• state (Statevector or DensityMatrix or ndarray) – an N-qubit quantum state.

• title (str) – a string that represents the plot title

• figsize (tuple) – Figure size in inches.

• color (list) – A list of len=2 giving colors for real and imaginary components of matrix elements.

• alpha (float) – Transparency value for bars

• ax_real (matplotlib.axes.Axes) – An optional Axes object to be used for the visualization output. If none is specified a new matplotlib Figure will be created and used. If this is specified without an ax_imag only the real component plot will be generated. Additionally, if specified there will be no returned Figure since it is redundant.

• ax_imag (matplotlib.axes.Axes) – An optional Axes object to be used for the visualization output. If none is specified a new matplotlib Figure will be created and used. If this is specified without an ax_real only the imaginary component plot will be generated. Additionally, if specified there will be no returned Figure since it is redundant.

戻り値

The matplotlib.Figure of the visualization if the ax_real and ax_imag kwargs are not set

戻り値の型

matplotlib.Figure

例外

• MissingOptionalLibraryError – Requires matplotlib.

• ValueError – When 『color』 is not a list of len=2.

• VisualizationError – if input is not a valid N-qubit state.

サンプル

# You can choose different colors for the real and imaginary parts of the density matrix.

from qiskit import QuantumCircuit
from qiskit.quantum_info import DensityMatrix
from qiskit.visualization import plot_state_city

qc = QuantumCircuit(2)
qc.h(0)
qc.cx(0, 1)

state = DensityMatrix(qc)
plot_state_city(state, color=['midnightblue', 'crimson'], title="New State City")

(Source code)

# You can make the bars more transparent to better see the ones that are behind
# if they overlap.

import numpy as np
from qiskit.quantum_info import Statevector
from qiskit.visualization import plot_state_city
from qiskit import QuantumCircuit

qc = QuantumCircuit(2)
qc.h(0)
qc.cx(0, 1)


qc = QuantumCircuit(2)
qc.h([0, 1])
qc.cz(0,1)
qc.ry(np.pi/3, 0)
qc.rx(np.pi/5, 1)

state = Statevector(qc)
plot_state_city(state, alpha=0.6)

(Source code)