Source code for pennylane.drawer.draw
# pylint: disable=too-many-arguments
# Copyright 2018-2021 Xanadu Quantum Technologies Inc.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
# http://www.apache.org/licenses/LICENSE-2.0
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""
Contains the drawing function.
"""
from functools import wraps
import warnings
import pennylane as qml
from .tape_mpl import tape_mpl
from .tape_text import tape_text
[docs]def draw(
qnode,
wire_order=None,
show_all_wires=False,
decimals=2,
max_length=100,
show_matrices=True,
expansion_strategy=None,
):
"""Create a function that draws the given qnode or quantum function.
Args:
qnode (.QNode or Callable): the input QNode or quantum function that is to be drawn.
wire_order (Sequence[Any]): the order (from top to bottom) to print the wires of the circuit
show_all_wires (bool): If True, all wires, including empty wires, are printed.
decimals (int): How many decimal points to include when formatting operation parameters.
``None`` will omit parameters from operation labels.
max_length (int): Maximum string width (columns) when printing the circuit
show_matrices=False (bool): show matrix valued parameters below all circuit diagrams
expansion_strategy (str): The strategy to use when circuit expansions or decompositions
are required. Note that this is ignored if the input is not a QNode.
- ``gradient``: The QNode will attempt to decompose
the internal circuit such that all circuit operations are supported by the gradient
method.
- ``device``: The QNode will attempt to decompose the internal circuit
such that all circuit operations are natively supported by the device.
Returns:
A function that has the same argument signature as ``qnode``. When called,
the function will draw the QNode/qfunc.
**Example**
.. code-block:: python3
@qml.qnode(qml.device('lightning.qubit', wires=2))
def circuit(a, w):
qml.Hadamard(0)
qml.CRX(a, wires=[0, 1])
qml.Rot(*w, wires=[1])
qml.CRX(-a, wires=[0, 1])
return qml.expval(qml.PauliZ(0) @ qml.PauliZ(1))
>>> print(qml.draw(circuit)(a=2.3, w=[1.2, 3.2, 0.7]))
0: ──H─╭●─────────────────────────────╭●─────────┤ ╭<Z@Z>
1: ────╰RX(2.30)──Rot(1.20,3.20,0.70)─╰RX(-2.30)─┤ ╰<Z@Z>
.. details::
:title: Usage Details
By specifying the ``decimals`` keyword, parameters are displayed to the specified precision.
>>> print(qml.draw(circuit, decimals=4)(a=2.3, w=[1.2, 3.2, 0.7]))
0: ──H─╭●─────────────────────────────────────╭●───────────┤ ╭<Z@Z>
1: ────╰RX(2.3000)──Rot(1.2000,3.2000,0.7000)─╰RX(-2.3000)─┤ ╰<Z@Z>
Parameters can be omitted by requesting ``decimals=None``:
>>> print(qml.draw(circuit, decimals=None)(a=2.3, w=[1.2, 3.2, 0.7]))
0: ──H─╭●───────╭●──┤ ╭<Z@Z>
1: ────╰RX──Rot─╰RX─┤ ╰<Z@Z>
If the parameters are not acted upon by classical processing like ``-a``, then
``qml.draw`` can handle string-valued parameters as well:
>>> @qml.qnode(qml.device('lightning.qubit', wires=1))
... def circuit2(x):
... qml.RX(x, wires=0)
... return qml.expval(qml.PauliZ(0))
>>> print(qml.draw(circuit2)("x"))
0: ──RX(x)─┤ <Z>
When requested with ``show_matrices=True`` (the default), matrix valued parameters
are printed below the circuit. For ``show_matrices=False``, they are not printed:
>>> @qml.qnode(qml.device('default.qubit', wires=2))
... def circuit3():
... qml.QubitUnitary(np.eye(2), wires=0)
... qml.QubitUnitary(-np.eye(4), wires=(0,1))
... return qml.expval(qml.Hermitian(np.eye(2), wires=1))
>>> print(qml.draw(circuit3)())
0: ──U(M0)─╭U(M1)─┤
1: ────────╰U(M1)─┤ <𝓗(M0)>
M0 =
[[1. 0.]
[0. 1.]]
M1 =
[[-1. -0. -0. -0.]
[-0. -1. -0. -0.]
[-0. -0. -1. -0.]
[-0. -0. -0. -1.]]
>>> print(qml.draw(circuit3, show_matrices=False)())
0: ──U(M0)─╭U(M1)─┤
1: ────────╰U(M1)─┤ <𝓗(M0)>
The ``max_length`` keyword warps long circuits:
.. code-block:: python
rng = np.random.default_rng(seed=42)
shape = qml.StronglyEntanglingLayers.shape(n_wires=3, n_layers=3)
params = rng.random(shape)
@qml.qnode(qml.device('lightning.qubit', wires=3))
def longer_circuit(params):
qml.StronglyEntanglingLayers(params, wires=range(3))
return [qml.expval(qml.PauliZ(i)) for i in range(3)]
print(qml.draw(longer_circuit, max_length=60)(params))
.. code-block:: none
0: ──Rot(0.77,0.44,0.86)─╭●────╭X──Rot(0.45,0.37,0.93)─╭●─╭X
1: ──Rot(0.70,0.09,0.98)─╰X─╭●─│───Rot(0.64,0.82,0.44)─│──╰●
2: ──Rot(0.76,0.79,0.13)────╰X─╰●──Rot(0.23,0.55,0.06)─╰X───
───Rot(0.83,0.63,0.76)──────────────────────╭●────╭X─┤ <Z>
──╭X────────────────────Rot(0.35,0.97,0.89)─╰X─╭●─│──┤ <Z>
──╰●────────────────────Rot(0.78,0.19,0.47)────╰X─╰●─┤ <Z>
The ``wire_order`` keyword specifies the order of the wires from
top to bottom:
>>> print(qml.draw(circuit, wire_order=[1,0])(a=2.3, w=[1.2, 3.2, 0.7]))
1: ────╭RX(2.30)──Rot(1.20,3.20,0.70)─╭RX(-2.30)─┤ ╭<Z@Z>
0: ──H─╰●─────────────────────────────╰●─────────┤ ╰<Z@Z>
If the device or ``wire_order`` has wires not used by operations, those wires are omitted
unless requested with ``show_all_wires=True``
>>> empty_qfunc = lambda : qml.expval(qml.PauliZ(0))
>>> empty_circuit = qml.QNode(empty_qfunc, qml.device('lightning.qubit', wires=3))
>>> print(qml.draw(empty_circuit, show_all_wires=True)())
0: ───┤ <Z>
1: ───┤
2: ───┤
Drawing also works on batch transformed circuits:
.. code-block:: python
@qml.gradients.param_shift(shifts=[(0.1,)])
@qml.qnode(qml.device('lightning.qubit', wires=1))
def transformed_circuit(x):
qml.RX(x, wires=0)
return qml.expval(qml.PauliZ(0))
print(qml.draw(transformed_circuit)(np.array(1.0, requires_grad=True)))
.. code-block:: none
0: ──RX(1.10)─┤ <Z>
0: ──RX(0.90)─┤ <Z>
The function also accepts quantum functions rather than QNodes. This can be especially
helpful if you want to visualize only a part of a circuit that may not be convertible into
a QNode, such as a sub-function that does not return any measurements.
>>> def qfunc(x):
... qml.RX(x, wires=[0])
... qml.CNOT(wires=[0, 1])
>>> print(qml.draw(qfunc)(1.1))
0: ──RX(1.10)─╭●─┤
1: ───────────╰X─┤
"""
if hasattr(qnode, "construct"):
return _draw_qnode(
qnode,
wire_order=wire_order,
show_all_wires=show_all_wires,
decimals=decimals,
max_length=max_length,
show_matrices=show_matrices,
expansion_strategy=expansion_strategy,
)
if expansion_strategy is not None:
warnings.warn(
"When the input to qml.draw is not a QNode, the expansion_strategy argument is ignored.",
UserWarning,
)
@wraps(qnode)
def wrapper(*args, **kwargs):
tape = qml.tape.make_qscript(qnode)(*args, **kwargs)
_wire_order = wire_order or tape.wires
return tape_text(
tape,
wire_order=_wire_order,
show_all_wires=show_all_wires,
decimals=decimals,
show_matrices=show_matrices,
max_length=max_length,
)
return wrapper
def _draw_qnode(
qnode,
wire_order=None,
show_all_wires=False,
decimals=2,
max_length=100,
show_matrices=True,
expansion_strategy=None,
):
@wraps(qnode)
def wrapper(*args, **kwargs):
original_expansion_strategy = getattr(qnode, "expansion_strategy", None)
try:
qnode.expansion_strategy = expansion_strategy or original_expansion_strategy
tapes = qnode.construct(args, kwargs)
finally:
qnode.expansion_strategy = original_expansion_strategy
_wire_order = wire_order or getattr(qnode.device, "wires", None)
if tapes is not None:
cache = {"tape_offset": 0, "matrices": []}
res = [
tape_text(
t,
wire_order=_wire_order,
show_all_wires=show_all_wires,
decimals=decimals,
show_matrices=False,
max_length=max_length,
cache=cache,
)
for t in tapes[0]
]
if show_matrices and cache["matrices"]:
mat_str = ""
for i, mat in enumerate(cache["matrices"]):
mat_str += f"\nM{i} = \n{mat}"
if mat_str:
mat_str = "\n" + mat_str
return "\n\n".join(res) + mat_str
return "\n\n".join(res)
return tape_text(
qnode.qtape,
wire_order=_wire_order,
show_all_wires=show_all_wires,
decimals=decimals,
show_matrices=show_matrices,
max_length=max_length,
)
return wrapper
[docs]def draw_mpl(
qnode,
wire_order=None,
show_all_wires=False,
decimals=None,
expansion_strategy=None,
style=None,
**kwargs,
):
"""Draw a qnode with matplotlib
Args:
qnode (.QNode or Callable): the input QNode/quantum function that is to be drawn.
Keyword Args:
wire_order (Sequence[Any]): the order (from top to bottom) to print the wires of the circuit
show_all_wires (bool): If True, all wires, including empty wires, are printed.
decimals (int): How many decimal points to include when formatting operation parameters.
Default ``None`` will omit parameters from operation labels.
style (str): visual style of plot. Valid strings are ``{'black_white', 'black_white_dark', 'sketch', 'pennylane',
'sketch_dark', 'solarized_light', 'solarized_dark', 'default'}``. If no style is specified, the
global style set with :func:`~.use_style` will be used, and the initial default is 'black_white'.
If you would like to use your environment's current rcParams, set `style` to "rcParams".
Setting style does not modify matplotlib global plotting settings.
fontsize (float or str): fontsize for text. Valid strings are
``{'xx-small', 'x-small', 'small', 'medium', large', 'x-large', 'xx-large'}``.
Default is ``14``.
wire_options (dict): matplotlib formatting options for the wire lines
label_options (dict): matplotlib formatting options for the wire labels
active_wire_notches (bool): whether or not to add notches indicating active wires.
Defaults to ``True``.
expansion_strategy (str): The strategy to use when circuit expansions or decompositions
are required.
- ``gradient``: The QNode will attempt to decompose
the internal circuit such that all circuit operations are supported by the gradient
method.
- ``device``: The QNode will attempt to decompose the internal circuit
such that all circuit operations are natively supported by the device.
Returns:
A function that has the same argument signature as ``qnode``. When called,
the function will draw the QNode as a tuple of (``matplotlib.figure.Figure``,
``matplotlib.axes._axes.Axes``)
**Example**:
.. code-block:: python
dev = qml.device('lightning.qubit', wires=(0,1,2,3))
@qml.qnode(dev)
def circuit(x, z):
qml.QFT(wires=(0,1,2,3))
qml.IsingXX(1.234, wires=(0,2))
qml.Toffoli(wires=(0,1,2))
qml.CSWAP(wires=(0,2,3))
qml.RX(x, wires=0)
qml.CRZ(z, wires=(3,0))
return qml.expval(qml.PauliZ(0))
fig, ax = qml.draw_mpl(circuit)(1.2345,1.2345)
fig.show()
.. figure:: ../../_static/draw_mpl/main_example.png
:align: center
:width: 60%
:target: javascript:void(0);
.. details::
:title: Usage Details
**Decimals:**
The keyword ``decimals`` controls how many decimal points to include when labelling the operations.
The default value ``None`` omits parameters for brevity.
.. code-block:: python
@qml.qnode(dev)
def circuit2(x, y):
qml.RX(x, wires=0)
qml.Rot(*y, wires=0)
return qml.expval(qml.PauliZ(0))
fig, ax = qml.draw_mpl(circuit2, decimals=2)(1.23456, [1.2345,2.3456,3.456])
fig.show()
.. figure:: ../../_static/draw_mpl/decimals.png
:align: center
:width: 60%
:target: javascript:void(0);
**Wires:**
The keywords ``wire_order`` and ``show_all_wires`` control the location of wires from top to bottom.
.. code-block:: python
fig, ax = qml.draw_mpl(circuit, wire_order=[3,2,1,0])(1.2345,1.2345)
fig.show()
.. figure:: ../../_static/draw_mpl/wire_order.png
:align: center
:width: 60%
:target: javascript:void(0);
If a wire is in ``wire_order``, but not in the ``tape``, it will be omitted by default. Only by selecting
``show_all_wires=True`` will empty wires be displayed.
.. code-block:: python
fig, ax = qml.draw_mpl(circuit, wire_order=["aux"], show_all_wires=True)(1.2345,1.2345)
fig.show()
.. figure:: ../../_static/draw_mpl/show_all_wires.png
:align: center
:width: 60%
:target: javascript:void(0);
**Integration with matplotlib:**
This function returns matplotlib figure and axes objects. Using these objects,
users can perform further customization of the graphic.
.. code-block:: python
fig, ax = qml.draw_mpl(circuit)(1.2345,1.2345)
fig.suptitle("My Circuit", fontsize="xx-large")
options = {'facecolor': "white", 'edgecolor': "#f57e7e", "linewidth": 6, "zorder": -1}
box1 = plt.Rectangle((-0.5, -0.5), width=3.0, height=4.0, **options)
ax.add_patch(box1)
ax.annotate("CSWAP", xy=(3, 2.5), xycoords='data', xytext=(3.8,1.5), textcoords='data',
arrowprops={'facecolor': 'black'}, fontsize=14)
fig.show()
.. figure:: ../../_static/draw_mpl/postprocessing.png
:align: center
:width: 60%
:target: javascript:void(0);
**Formatting:**
PennyLane has inbuilt styles for controlling the appearance of the circuit drawings.
All available styles can be determined by evaluating ``qml.drawer.available_styles()``.
Any available string can then be passed via the kwarg ``style`` to change the settings for
that plot. This will not affect style settings for subsequent matplotlib plots.
.. code-block:: python
fig, ax = qml.draw_mpl(circuit, style='sketch')(1.2345,1.2345)
fig.show()
.. figure:: ../../_static/draw_mpl/sketch_style.png
:align: center
:width: 60%
:target: javascript:void(0);
You can also control the appearance with matplotlib's provided tools, see the
`matplotlib docs <https://matplotlib.org/stable/tutorials/introductory/customizing.html>`_ .
For example, we can customize ``plt.rcParams``. To use a customized appearance based on matplotlib's
``plt.rcParams``, ``qml.draw_mpl`` must be run with ``style=None``:
.. code-block:: python
plt.rcParams['patch.facecolor'] = 'mistyrose'
plt.rcParams['patch.edgecolor'] = 'maroon'
plt.rcParams['text.color'] = 'maroon'
plt.rcParams['font.weight'] = 'bold'
plt.rcParams['patch.linewidth'] = 4
plt.rcParams['patch.force_edgecolor'] = True
plt.rcParams['lines.color'] = 'indigo'
plt.rcParams['lines.linewidth'] = 5
plt.rcParams['figure.facecolor'] = 'ghostwhite'
fig, ax = qml.draw_mpl(circuit, style=None)(1.2345,1.2345)
fig.show()
.. figure:: ../../_static/draw_mpl/rcparams.png
:align: center
:width: 60%
:target: javascript:void(0);
The wires and wire labels can be manually formatted by passing in dictionaries of
keyword-value pairs of matplotlib options. ``wire_options`` accepts options for lines,
and ``label_options`` accepts text options.
.. code-block:: python
fig, ax = qml.draw_mpl(circuit, wire_options={'color':'teal', 'linewidth': 5},
label_options={'size': 20})(1.2345,1.2345)
fig.show()
.. figure:: ../../_static/draw_mpl/wires_labels.png
:align: center
:width: 60%
:target: javascript:void(0);
"""
if hasattr(qnode, "construct"):
return _draw_mpl_qnode(
qnode,
wire_order=wire_order,
show_all_wires=show_all_wires,
decimals=decimals,
expansion_strategy=expansion_strategy,
style=style,
**kwargs,
)
if expansion_strategy is not None:
warnings.warn(
"When the input to qml.draw is not a QNode, the expansion_strategy argument is ignored.",
UserWarning,
)
@wraps(qnode)
def wrapper(*args, **kwargs):
tape = qml.tape.make_qscript(qnode)(*args, **kwargs)
_wire_order = wire_order or tape.wires
return tape_mpl(
tape,
wire_order=_wire_order,
show_all_wires=show_all_wires,
decimals=decimals,
style=style,
**kwargs,
)
return wrapper
def _draw_mpl_qnode(
qnode,
wire_order=None,
show_all_wires=False,
decimals=None,
expansion_strategy=None,
style="black_white",
**kwargs,
):
@wraps(qnode)
def wrapper(*args, **kwargs_qnode):
original_expansion_strategy = getattr(qnode, "expansion_strategy", None)
try:
qnode.expansion_strategy = expansion_strategy or original_expansion_strategy
qnode.construct(args, kwargs_qnode)
finally:
qnode.expansion_strategy = original_expansion_strategy
_wire_order = wire_order or getattr(qnode.device, "wires", None)
return tape_mpl(
qnode.qtape,
wire_order=_wire_order,
show_all_wires=show_all_wires,
decimals=decimals,
style=style,
**kwargs,
)
return wrapper
_modules/pennylane/drawer/draw
Download Python script
Download Notebook
View on GitHub