def plot_bloch_vector(bloch, title="", ax=None, figsize=None):
"""Plot the Bloch sphere.
Plot a sphere, axes, the Bloch vector, and its projections onto each axis.
Args:
bloch (list[double]): array of three elements where [<x>, <y>, <z>]
title (str): a string that represents the plot title
ax (matplotlib.Axes): An Axes to use for rendering the bloch sphere
figsize (tuple): Figure size in inches. Has no effect is passing `ax`.
Returns:
Figure: A matplotlib figure instance if `ax = None`.
Raises:
ImportError: Requires matplotlib.
"""
if not HAS_MATPLOTLIB:
raise ImportError('Must have Matplotlib installed.')
if figsize is None:
figsize = (5, 5)
B = Bloch(axes=ax)
B.add_vectors(bloch)
B.render(title=title)
if ax is None:
fig = B.fig
fig.set_size_inches(figsize[0], figsize[1])
plt.close(fig)
return fig
return None
def plot_bloch_vector(bloch, title="", ax=None, figsize=None, coord_type="cartesian"):
"""Plot the Bloch sphere.
Plot a sphere, axes, the Bloch vector, and its projections onto each axis.
Args:
bloch (list[double]): array of three elements where [<x>, <y>, <z>] (Cartesian)
or [<r>, <theta>, <phi>] (spherical in radians)
<theta> is inclination angle from +z direction
<phi> is azimuth from +x direction
title (str): a string that represents the plot title
ax (matplotlib.axes.Axes): An Axes to use for rendering the bloch
sphere
figsize (tuple): Figure size in inches. Has no effect is passing ``ax``.
coord_type (str): a string that specifies coordinate type for bloch
(Cartesian or spherical), default is Cartesian
Returns:
Figure: A matplotlib figure instance if ``ax = None``.
Raises:
MissingOptionalLibraryError: Requires matplotlib.
Example:
.. jupyter-execute::
from qiskit.visualization import plot_bloch_vector
%matplotlib inline
plot_bloch_vector([0,1,0], title="New Bloch Sphere")
"""
if not HAS_MATPLOTLIB:
raise MissingOptionalLibraryError(
libname="Matplotlib",
name="plot_bloch_vector",
pip_install="pip install matplotlib",
)
from qiskit.visualization.bloch import Bloch
from matplotlib import get_backend
from matplotlib import pyplot as plt
if figsize is None:
figsize = (5, 5)
B = Bloch(axes=ax)
if coord_type == "spherical":
r, theta, phi = bloch[0], bloch[1], bloch[2]
bloch[0] = r * np.sin(theta) * np.cos(phi)
bloch[1] = r * np.sin(theta) * np.sin(phi)
bloch[2] = r * np.cos(theta)
B.add_vectors(bloch)
B.render(title=title)
if ax is None:
fig = B.fig
fig.set_size_inches(figsize[0], figsize[1])
if get_backend() in ["module://ipykernel.pylab.backend_inline", "nbAgg"]:
plt.close(fig)
return fig
return None
def plot_bloch_vector(bloch, title="", ax=None, figsize=None):
"""Plot the Bloch sphere.
Plot a sphere, axes, the Bloch vector, and its projections onto each axis.
Args:
bloch (list[double]): array of three elements where [<x>, <y>, <z>]
title (str): a string that represents the plot title
ax (matplotlib.axes.Axes): An Axes to use for rendering the bloch
sphere
figsize (tuple): Figure size in inches. Has no effect is passing ``ax``.
Returns:
Figure: A matplotlib figure instance if ``ax = None``.
Raises:
ImportError: Requires matplotlib.
Example:
.. jupyter-execute::
from qiskit.visualization import plot_bloch_vector
%matplotlib inline
plot_bloch_vector([0,1,0], title="New Bloch Sphere")
"""
if not HAS_MATPLOTLIB:
raise ImportError('Must have Matplotlib installed. To install, run '
'"pip install matplotlib".')
if figsize is None:
figsize = (5, 5)
B = Bloch(axes=ax)
B.add_vectors(bloch)
B.render(title=title)
if ax is None:
fig = B.fig
fig.set_size_inches(figsize[0], figsize[1])
if get_backend() in [
'module://ipykernel.pylab.backend_inline', 'nbAgg'
]:
plt.close(fig)
return fig
return None