qiskit.visualization.dag_drawer

dag_drawer(dag, scale=0.7, filename=None, style='color') GitHub(opens in a new tab)

Plot the directed acyclic graph (dag) to represent operation dependencies in a quantum circuit.

Note this function leverages pydot(opens in a new tab) to generate the graph, which means that having Graphviz(opens in a new tab) installed on your system is required for this to work.

The current release of Graphviz can be downloaded here: <https://graphviz.gitlab.io/download/(opens in a new tab)>. Download the version of the software that matches your environment and follow the instructions to install Graph Visualization Software (Graphviz) on your operating system.

Parameters

• 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

if in Jupyter notebook and not saving to file,

otherwise None.

Return type

PIL.Image

Raises

• VisualizationError – when style is not recognized.
• MissingOptionalLibraryError – when pydot or pillow are not installed.

Example

%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)