English
Languages
English
Bengali
French
German
Japanese
Korean
Portuguese
Spanish
Tamil

Source code for qiskit.visualization.dag_visualization

# This code is part of Qiskit.
#
# (C) Copyright IBM 2017, 2018, 2020.
#
# This code is licensed under the Apache License, Version 2.0. You may
# obtain a copy of this license in the LICENSE.txt file in the root directory
# of this source tree or at http://www.apache.org/licenses/LICENSE-2.0.
#
# Any modifications or derivative works of this code must retain this
# copyright notice, and modified files need to carry a notice indicating
# that they have been altered from the originals.

# pylint: disable=invalid-name

"""
Visualization function for DAG circuit representation.
"""
from retworkx.visualization import graphviz_draw  # pylint: disable=no-name-in-module,import-error

from qiskit.dagcircuit.dagnode import DAGOpNode, DAGInNode, DAGOutNode
from qiskit.circuit import Qubit
from qiskit.utils import optionals as _optionals
from qiskit.exceptions import InvalidFileError
from .exceptions import VisualizationError


[docs]@_optionals.HAS_GRAPHVIZ.require_in_call def dag_drawer(dag, scale=0.7, filename=None, style="color"): """Plot the directed acyclic graph (dag) to represent operation dependencies in a quantum circuit. This function calls the :func:`~retworkx.visualization.graphviz_draw` function from the ``retworkx`` package to draw the DAG. Args: dag (DAGCircuit): The dag to draw. scale (float): scaling factor filename (str): file path to save image to (format inferred from name) style (str): 'plain': B&W graph 'color' (default): color input/output/op nodes Returns: PIL.Image: if in Jupyter notebook and not saving to file, otherwise None. Raises: VisualizationError: when style is not recognized. InvalidFileError: when filename provided is not valid Example: .. jupyter-execute:: %matplotlib inline from qiskit import QuantumRegister, ClassicalRegister, QuantumCircuit from qiskit.dagcircuit import DAGCircuit from qiskit.converters import circuit_to_dag from qiskit.visualization import dag_drawer q = QuantumRegister(3, 'q') c = ClassicalRegister(3, 'c') circ = QuantumCircuit(q, c) circ.h(q[0]) circ.cx(q[0], q[1]) circ.measure(q[0], c[0]) circ.rz(0.5, q[1]).c_if(c, 2) dag = circuit_to_dag(circ) dag_drawer(dag) """ # NOTE: use type str checking to avoid potential cyclical import # the two tradeoffs ere that it will not handle subclasses and it is # slower (which doesn't matter for a visualization function) type_str = str(type(dag)) if "DAGDependency" in type_str: graph_attrs = {"dpi": str(100 * scale)} def node_attr_func(node): if style == "plain": return {} if style == "color": n = {} n["label"] = str(node.node_id) + ": " + str(node.name) if node.name == "measure": n["color"] = "blue" n["style"] = "filled" n["fillcolor"] = "lightblue" if node.name == "barrier": n["color"] = "black" n["style"] = "filled" n["fillcolor"] = "green" if getattr(node.op, "_directive", False): n["color"] = "black" n["style"] = "filled" n["fillcolor"] = "red" if getattr(node.op, "condition", None): n["label"] = str(node.node_id) + ": " + str(node.name) + " (conditional)" n["color"] = "black" n["style"] = "filled" n["fillcolor"] = "lightgreen" return n else: raise VisualizationError("Unrecognized style %s for the dag_drawer." % style) edge_attr_func = None else: qubit_indices = {bit: index for index, bit in enumerate(dag.qubits)} clbit_indices = {bit: index for index, bit in enumerate(dag.clbits)} register_bit_labels = { bit: f"{reg.name}[{idx}]" for reg in list(dag.qregs.values()) + list(dag.cregs.values()) for (idx, bit) in enumerate(reg) } graph_attrs = {"dpi": str(100 * scale)} def node_attr_func(node): if style == "plain": return {} if style == "color": n = {} if isinstance(node, DAGOpNode): n["label"] = node.name n["color"] = "blue" n["style"] = "filled" n["fillcolor"] = "lightblue" if isinstance(node, DAGInNode): if isinstance(node.wire, Qubit): label = register_bit_labels.get(node.wire, f"q_{qubit_indices[node.wire]}") else: label = register_bit_labels.get(node.wire, f"c_{clbit_indices[node.wire]}") n["label"] = label n["color"] = "black" n["style"] = "filled" n["fillcolor"] = "green" if isinstance(node, DAGOutNode): if isinstance(node.wire, Qubit): label = register_bit_labels.get(node.wire, f"q[{qubit_indices[node.wire]}]") else: label = register_bit_labels.get(node.wire, f"c[{clbit_indices[node.wire]}]") n["label"] = label n["color"] = "black" n["style"] = "filled" n["fillcolor"] = "red" return n else: raise VisualizationError("Invalid style %s" % style) def edge_attr_func(edge): e = {} if isinstance(edge, Qubit): label = register_bit_labels.get(edge, f"q_{qubit_indices[edge]}") else: label = register_bit_labels.get(edge, f"c_{clbit_indices[edge]}") e["label"] = label return e image_type = None if filename: if "." not in filename: raise InvalidFileError("Parameter 'filename' must be in format 'name.extension'") image_type = filename.split(".")[-1] return graphviz_draw( dag._multi_graph, node_attr_func, edge_attr_func, graph_attrs, filename, image_type, )