def matrix_histogram_complex(M, xlabels=None, ylabels=None,
title=None, limits=None, phase_limits=None,
colorbar=True, fig=None, ax=None,
threshold=None):
"""
Draw a histogram for the amplitudes of matrix M, using the argument
of each element for coloring the bars, with the given x and y labels
and title.
Parameters
----------
M : Matrix of Qobj
The matrix to visualize
xlabels : list of strings
list of x labels
ylabels : list of strings
list of y labels
title : string
title of the plot (optional)
limits : list/array with two float numbers
The z-axis limits [min, max] (optional)
phase_limits : list/array with two float numbers
The phase-axis (colorbar) limits [min, max] (optional)
ax : a matplotlib axes instance
The axes context in which the plot will be drawn.
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.
Raises
------
ValueError
Input argument is not valid.
"""
if isinstance(M, Qobj):
# extract matrix data from Qobj
M = M.full()
n = np.size(M)
xpos, ypos = np.meshgrid(range(M.shape[0]), range(M.shape[1]))
xpos = xpos.T.flatten() - 0.5
ypos = ypos.T.flatten() - 0.5
zpos = np.zeros(n)
dx = dy = 0.8 * np.ones(n)
Mvec = M.flatten()
dz = abs(Mvec)
# make small numbers real, to avoid random colors
idx, = np.where(abs(Mvec) < 0.001)
Mvec[idx] = abs(Mvec[idx])
if phase_limits: # check that limits is a list type
phase_min = phase_limits[0]
phase_max = phase_limits[1]
else:
phase_min = -pi
phase_max = pi
norm = mpl.colors.Normalize(phase_min, phase_max)
cmap = complex_phase_cmap()
colors = cmap(norm(angle(Mvec)))
if threshold is not None:
colors[:, 3] = 1 * (dz > threshold)
if ax is None:
fig = plt.figure()
ax = Axes3D(fig, azim=-35, elev=35)
ax.bar3d(xpos, ypos, zpos, dx, dy, dz, color=colors)
if title and fig:
ax.set_title(title)
# x axis
ax.axes.w_xaxis.set_major_locator(plt.IndexLocator(1, -0.5))
if xlabels:
ax.set_xticklabels(xlabels)
ax.tick_params(axis='x', labelsize=12)
# y axis
ax.axes.w_yaxis.set_major_locator(plt.IndexLocator(1, -0.5))
if ylabels:
ax.set_yticklabels(ylabels)
ax.tick_params(axis='y', labelsize=12)
# z axis
if limits and isinstance(limits, list):
ax.set_zlim3d(limits)
else:
ax.set_zlim3d([0, 1]) # use min/max
# ax.set_zlabel('abs')
# color axis
if colorbar:
cax, kw = mpl.colorbar.make_axes(ax, shrink=.75, pad=.0)
cb = mpl.colorbar.ColorbarBase(cax, cmap=cmap, norm=norm)
cb.set_ticks([-pi, -pi / 2, 0, pi / 2, pi])
cb.set_ticklabels(
(r'$-\pi$', r'$-\pi/2$', r'$0$', r'$\pi/2$', r'$\pi$'))
cb.set_label('arg')
return fig, ax
def matrix_histogram_complex(M,
xlabels=None,
ylabels=None,
title=None,
limits=None,
phase_limits=None,
colorbar=True,
fig=None,
ax=None,
threshold=None):
"""
Draw a histogram for the amplitudes of matrix M, using the argument
of each element for coloring the bars, with the given x and y labels
and title.
Parameters
----------
M : Matrix of Qobj
The matrix to visualize
xlabels : list of strings
list of x labels
ylabels : list of strings
list of y labels
title : string
title of the plot (optional)
limits : list/array with two float numbers
The z-axis limits [min, max] (optional)
phase_limits : list/array with two float numbers
The phase-axis (colorbar) limits [min, max] (optional)
ax : a matplotlib axes instance
The axes context in which the plot will be drawn.
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.
Raises
------
ValueError
Input argument is not valid.
"""
if isinstance(M, Qobj):
# extract matrix data from Qobj
M = M.full()
n = np.size(M)
xpos, ypos = np.meshgrid(range(M.shape[0]), range(M.shape[1]))
xpos = xpos.T.flatten() - 0.5
ypos = ypos.T.flatten() - 0.5
zpos = np.zeros(n)
dx = dy = 0.8 * np.ones(n)
Mvec = M.flatten()
dz = abs(Mvec)
# make small numbers real, to avoid random colors
idx, = np.where(abs(Mvec) < 0.001)
Mvec[idx] = abs(Mvec[idx])
if phase_limits: # check that limits is a list type
phase_min = phase_limits[0]
phase_max = phase_limits[1]
else:
phase_min = -pi
phase_max = pi
norm = mpl.colors.Normalize(phase_min, phase_max)
cmap = complex_phase_cmap()
colors = cmap(norm(angle(Mvec)))
if threshold is not None:
colors[:, 3] = 1 * (dz > threshold)
if ax is None:
fig = plt.figure()
ax = Axes3D(fig, azim=-35, elev=35)
ax.bar3d(xpos, ypos, zpos, dx, dy, dz, color=colors)
if title and fig:
ax.set_title(title)
# x axis
ax.axes.w_xaxis.set_major_locator(plt.IndexLocator(1, -0.5))
if xlabels:
ax.set_xticklabels(xlabels)
ax.tick_params(axis='x', labelsize=12)
# y axis
ax.axes.w_yaxis.set_major_locator(plt.IndexLocator(1, -0.5))
if ylabels:
ax.set_yticklabels(ylabels)
ax.tick_params(axis='y', labelsize=12)
# z axis
if limits and isinstance(limits, list):
ax.set_zlim3d(limits)
else:
ax.set_zlim3d([0, 1]) # use min/max
# ax.set_zlabel('abs')
# color axis
if colorbar:
cax, kw = mpl.colorbar.make_axes(ax, shrink=.75, pad=.0)
cb = mpl.colorbar.ColorbarBase(cax, cmap=cmap, norm=norm)
cb.set_ticks([-pi, -pi / 2, 0, pi / 2, pi])
cb.set_ticklabels(
(r'$-\pi$', r'$-\pi/2$', r'$0$', r'$\pi/2$', r'$\pi$'))
cb.set_label('arg')
return fig, ax