def process_data(rho):
""" Sort rho data """
result = dict()
num = int(np.log2(len(rho)))
labels = list(map(lambda x: x.to_label(), pauli_group(num)))
values = list(map(lambda x: np.real(np.trace(np.dot(x.to_matrix(), rho))),
pauli_group(num)))
for position, label in enumerate(labels):
result[label] = values[position]
return result
def plot_state_paulivec(rho, title="", figsize=None, color=None):
"""Plot the paulivec representation of a quantum state.
Plot a bargraph of the mixed state rho over the pauli matrices
Args:
rho (ndarray): Numpy array for state vector or density matrix
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.
Returns:
matplotlib.Figure: The matplotlib.Figure of the visualization
Raises:
ImportError: Requires matplotlib.
"""
if not HAS_MATPLOTLIB:
raise ImportError('Must have Matplotlib installed.')
rho = _validate_input_state(rho)
if figsize is None:
figsize = (7, 5)
num = int(np.log2(len(rho)))
labels = list(map(lambda x: x.to_label(), pauli_group(num)))
values = list(
map(lambda x: np.real(np.trace(np.dot(x.to_matrix(), rho))),
pauli_group(num)))
numelem = len(values)
if color is None:
color = "#648fff"
ind = np.arange(numelem) # the x locations for the groups
width = 0.5 # the width of the bars
fig, ax = plt.subplots(figsize=figsize)
ax.grid(zorder=0, linewidth=1, linestyle='--')
ax.bar(ind, values, width, color=color, zorder=2)
ax.axhline(linewidth=1, color='k')
# add some text for labels, title, and axes ticks
ax.set_ylabel('Expectation value', fontsize=14)
ax.set_xticks(ind)
ax.set_yticks([-1, -0.5, 0, 0.5, 1])
ax.set_xticklabels(labels, fontsize=14, rotation=70)
ax.set_xlabel('Pauli', fontsize=14)
ax.set_ylim([-1, 1])
ax.set_facecolor('#eeeeee')
for tick in ax.xaxis.get_major_ticks() + ax.yaxis.get_major_ticks():
tick.label.set_fontsize(14)
ax.set_title(title, fontsize=16)
if get_backend() in ['module://ipykernel.pylab.backend_inline', 'nbAgg']:
plt.close(fig)
return fig
def plot_state_paulivec(rho, title="", figsize=None, color=None, ax=None):
"""Plot the paulivec representation of a quantum state.
Plot a bargraph of the mixed state rho over the pauli matrices
Args:
rho (ndarray): Numpy array for state vector or density matrix
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:
matplotlib.Figure:
The matplotlib.Figure of the visualization if the
``ax`` kwarg is not set
Raises:
ImportError: Requires matplotlib.
Example:
.. jupyter-execute::
from qiskit import QuantumCircuit, BasicAer, execute
from qiskit.visualization import plot_state_paulivec
%matplotlib inline
qc = QuantumCircuit(2, 2)
qc.h(0)
qc.cx(0, 1)
qc.measure([0, 1], [0, 1])
backend = BasicAer.get_backend('statevector_simulator')
job = execute(qc, backend).result()
plot_state_paulivec(job.get_statevector(qc), color='midnightblue',
title="New PauliVec plot")
"""
if not HAS_MATPLOTLIB:
raise ImportError('Must have Matplotlib installed.')
rho = _validate_input_state(rho)
if figsize is None:
figsize = (7, 5)
num = int(np.log2(len(rho)))
labels = list(map(lambda x: x.to_label(), pauli_group(num)))
values = list(
map(lambda x: np.real(np.trace(np.dot(x.to_matrix(), rho))),
pauli_group(num)))
numelem = len(values)
if color is None:
color = "#648fff"
ind = np.arange(numelem) # the x locations for the groups
width = 0.5 # the width of the bars
if ax is None:
return_fig = True
fig, ax = plt.subplots(figsize=figsize)
else:
return_fig = False
fig = ax.get_figure()
ax.grid(zorder=0, linewidth=1, linestyle='--')
ax.bar(ind, values, width, color=color, zorder=2)
ax.axhline(linewidth=1, color='k')
# add some text for labels, title, and axes ticks
ax.set_ylabel('Expectation value', fontsize=14)
ax.set_xticks(ind)
ax.set_yticks([-1, -0.5, 0, 0.5, 1])
ax.set_xticklabels(labels, fontsize=14, rotation=70)
ax.set_xlabel('Pauli', fontsize=14)
ax.set_ylim([-1, 1])
ax.set_facecolor('#eeeeee')
for tick in ax.xaxis.get_major_ticks() + ax.yaxis.get_major_ticks():
tick.label.set_fontsize(14)
ax.set_title(title, fontsize=16)
if return_fig:
if get_backend() in [
'module://ipykernel.pylab.backend_inline', 'nbAgg'
]:
plt.close(fig)
return fig
