qiskit.visualization.plot_state_paulivec¶
- plot_state_paulivec(state, title='', figsize=None, color=None, ax=None, *, rho=None, filename=None)[source]¶
Plot the paulivec representation of a quantum state.
Plot a bargraph of the mixed state rho over the pauli matrices
- Parameters
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 or str) -- Color of the expectation value bars.
ax (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. Additionally, if specified there will be no returned Figure since it is redundant.
- Returns
The matplotlib.Figure of the visualization if the
ax
kwarg is not set- Return type
matplotlib.Figure
- Raises
MissingOptionalLibraryError -- Requires matplotlib.
VisualizationError -- if input is not a valid N-qubit state.
Examples
# You can set a color for all the bars. from qiskit import QuantumCircuit from qiskit.quantum_info import Statevector from qiskit.visualization import plot_state_paulivec qc = QuantumCircuit(2) qc.h(0) qc.cx(0, 1) state = Statevector(qc) plot_state_paulivec(state, color='midnightblue', title="New PauliVec plot")
# If you introduce a list with less colors than bars, the color of the bars will # alternate following the sequence from the list. import numpy as np from qiskit.quantum_info import DensityMatrix qc = QuantumCircuit(2) qc.h([0, 1]) qc.cz(0, 1) qc.ry(np.pi/3, 0) qc.rx(np.pi/5, 1) matrix = DensityMatrix(qc) plot_state_paulivec(matrix, color=['crimson', 'midnightblue', 'seagreen'])