qiskit.visualization.plot_state_city

qiskit.visualization.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.

Obsolète depuis la version 0.15.1: 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.

Paramètres:

• 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.

Renvoie:

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

Type renvoyé:

matplotlib.figure.Figure

Lève:

• MissingOptionalLibraryError – Requires matplotlib.

• ValueError – When “color” is not a list of len=2.

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

Exemples

# 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)