def qpt_plot(chi, lbls_list, title=None, fig=None, axes=None):
"""
Visualize the quantum process tomography chi matrix. Plot the real and
imaginary parts separately.
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.
axes : list of figure axis instance
User defined figure axis instance (list of two axes) used for
generating QPT plot.
Returns
-------
fig, ax : tuple
A tuple of the matplotlib figure and axes instances used to produce
the figure.
"""
if axes is None or len(axes) != 2:
if fig is None:
fig = plt.figure(figsize=(16, 8))
ax1 = fig.add_subplot(1, 2, 1, projection='3d', position=[0, 0, 1, 1])
ax2 = fig.add_subplot(1, 2, 2, projection='3d', position=[0, 0, 1, 1])
axes = [ax1, ax2]
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))]))
matrix_histogram(real(chi),
xlabels,
xlabels,
title=r"real($\chi$)",
limits=[-1, 1],
ax=axes[0])
matrix_histogram(imag(chi),
xlabels,
xlabels,
title=r"imag($\chi$)",
limits=[-1, 1],
ax=axes[1])
if title and fig:
fig.suptitle(title)
return fig, axes
def qpt_plot(chi, lbls_list, title=None, fig=None, axes=None):
"""
Visualize the quantum process tomography chi matrix. Plot the real and
imaginary parts separately.
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.
axes : list of figure axis instance
User defined figure axis instance (list of two axes) used for
generating QPT plot.
Returns
-------
fig, ax : tuple
A tuple of the matplotlib figure and axes instances used to produce
the figure.
"""
if axes is None or len(axes) != 2:
if fig is None:
fig = plt.figure(figsize=(16, 8))
ax1 = fig.add_subplot(1, 2, 1, projection='3d', position=[0, 0, 1, 1])
ax2 = fig.add_subplot(1, 2, 2, projection='3d', position=[0, 0, 1, 1])
axes = [ax1, ax2]
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))]))
matrix_histogram(real(chi), xlabels, xlabels,
title=r"real($\chi$)", limits=[-1, 1], ax=axes[0])
matrix_histogram(imag(chi), xlabels, xlabels,
title=r"imag($\chi$)", limits=[-1, 1], ax=axes[1])
if title and fig:
fig.suptitle(title)
return fig, axes
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)