def plot_density_matrices(self):
from mpl_toolkits.mplot3d import Axes3D # noqa: F401 unused import
from qutip.visualization import matrix_histogram_complex
fig = plt.figure()
axs = [1, 2]
axs = list(map(lambda x: fig.add_subplot(1, 2, x, projection="3d"), axs))
fig.canvas.set_window_title(self._name + " F = {:.4f}".format(self._fidelity))
matrix_histogram_complex(self._expect_dm, ax=axs[0])
matrix_histogram_complex(self._experiment_rho, ax=axs[1])
def qpt_plot_combined(chi, lbls_list, title=None,
fig=None, ax=None, figsize=(8, 6),
threshold=None):
"""
Visualize the quantum process tomography chi matrix. Plot bars with
height and color corresponding to the absolute value and phase,
respectively.
Parameters
----------
chi : array
Input QPT chi matrix.
lbls_list : list
List of labels for QPT plot axes.
title : string
Plot title.
fig : figure instance
User defined figure instance used for generating QPT plot.
ax : figure axis instance
User defined figure axis instance used for generating QPT plot
(alternative to the fig argument).
threshold: float (None)
Threshold for when bars of smaller height should be transparent. If
not set, all bars are colored according to the color map.
Returns
-------
fig, ax : tuple
A tuple of the matplotlib figure and axes instances used to produce
the figure.
"""
if ax is None:
if fig is None:
fig = plt.figure(figsize=figsize)
ax = fig.add_subplot(1, 1, 1, projection='3d', position=[0, 0, 1, 1])
xlabels = []
for inds in _index_permutations([len(lbls) for lbls in lbls_list]):
xlabels.append("".join(
[lbls_list[k][inds[k]] for k in range(len(lbls_list))]))
if not title:
title = r"$\chi$"
matrix_histogram_complex(chi, xlabels, xlabels, title=title, ax=ax,
threshold=threshold)
return fig, ax
def qpt_plot_combined(chi, lbls_list, title=None, fig=None, ax=None):
"""
Visualize the quantum process tomography chi matrix. Plot bars with
height and color corresponding to the absolute value and phase,
respectively.
Parameters
----------
chi : array
Input QPT chi matrix.
lbls_list : list
List of labels for QPT plot axes.
title : string
Plot title.
fig : figure instance
User defined figure instance used for generating QPT plot.
ax : figure axis instance
User defined figure axis instance used for generating QPT plot
(alternative to the fig argument).
Returns
-------
An matplotlib figure instance for the plot.
"""
if ax is None:
if fig is None:
fig = plt.figure(figsize=(8, 6))
ax = fig.add_subplot(1, 1, 1, projection='3d', position=[0, 0, 1, 1])
xlabels = []
for inds in _index_permutations([len(lbls) for lbls in lbls_list]):
xlabels.append("".join(
[lbls_list[k][inds[k]] for k in range(len(lbls_list))]))
if not title:
title = r"$\chi$"
matrix_histogram_complex(chi, xlabels, xlabels, title=title, ax=ax)
return fig
def dmat_hist(rho, obj='all', ind=None, im=False):
"""Plots 3D histogram of specified density matrix.
Parameters:
-----------
rho: qutip.Result.states
density matrices per time instant
obj: int
Index of desired object in quantum system
ind: int
Index of specific density matrix to plot when rho is of qutip.Result.states format
im: boolean
Include imaginary part
"""
if isinstance(rho, list):
dm = rho[ind]
else:
dm = rho
if obj != 'all':
if not isinstance(obj, int):
raise ValueError("Give integer value for 'obj'")
dm = dm.ptrace(obj)
if obj == 0:
title = "Histogram of density matrix of qubit"
elif (isinstance(obj, int) and obj > 0):
title = "Histogram of density matrix of cavity {}".format(obj)
elif obj == 'all':
title = "Histogram of density matrix of total system"
if im:
matrix_histogram_complex(dm.full(), title=title)
else:
matrix_histogram(dm.full().real, title=title)