Adjust graphviz options for better layout with plot_gate_map() (#12770)…

… (#13089) * Adjust graphviz options for better layout with plot_gate_map() This commit fixes an issue with the visualizations of some backends/coupling maps. The default neato settings worked well in most cases but for some graphs it was not generating a good layout. This tweaks the settings a bit so that layouts work with more classes of graphs. * Don't set graph attributes if qubit_coordinates is set * adjust sizes * planar branching * support for backendv1 * remove the formula * new ref images --------- Co-authored-by: Luciano Bello <[email protected]> Co-authored-by: Elena Peña Tapia <[email protected]> (cherry picked from commit 52733ae) Co-authored-by: Matthew Treinish <[email protected]>
Qiskit · Sep 5, 2024 · 584ee9a · 584ee9a
1 parent 722eba2
commit 584ee9a
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Showing 30 changed files with 40 additions and 12 deletions.
diff --git a/qiskit/visualization/gate_map.py b/qiskit/visualization/gate_map.py
@@ -945,6 +945,7 @@ def plot_gate_map(
         font_color,
         ax,
         filename,
+        planar=rx.is_planar(coupling_map.graph.to_undirected(multigraph=False)),
     )
 
 
@@ -966,6 +967,8 @@ def plot_coupling_map(
     font_color="white",
     ax=None,
     filename=None,
+    *,
+    planar=True,
 ):
     """Plots an arbitrary coupling map of qubits (embedded in a plane).
 
@@ -987,6 +990,7 @@ def plot_coupling_map(
         font_color (str): The font color for the qubit labels.
         ax (Axes): A Matplotlib axes instance.
         filename (str): file path to save image to.
+        planar (bool): If the coupling map is planar or not. Default: ``True`` (i.e. it is planar)
 
     Returns:
         Figure: A Matplotlib figure instance.
@@ -1057,16 +1061,21 @@ def plot_coupling_map(
 
     if font_size is None:
         max_characters = max(1, max(len(str(x)) for x in qubit_labels))
-        font_size = max(int(20 / max_characters), 1)
+        if max_characters == 1:
+            font_size = 20
+        elif max_characters == 2:
+            font_size = 14
+        elif max_characters == 3:
+            font_size = 12
+        else:
+            font_size = 1
 
     def color_node(node):
         if qubit_coordinates:
             out_dict = {
                 "label": str(qubit_labels[node]),
                 "color": f'"{qubit_color[node]}"',
                 "fillcolor": f'"{qubit_color[node]}"',
-                "style": "filled",
-                "shape": "circle",
                 "pos": f'"{qubit_coordinates[node][0]},{qubit_coordinates[node][1]}"',
                 "pin": "True",
             }
@@ -1075,11 +1084,11 @@ def color_node(node):
                 "label": str(qubit_labels[node]),
                 "color": f'"{qubit_color[node]}"',
                 "fillcolor": f'"{qubit_color[node]}"',
-                "style": "filled",
-                "shape": "circle",
             }
+        out_dict["style"] = "filled"
+        out_dict["shape"] = "circle"
         out_dict["fontcolor"] = f'"{font_color}"'
-        out_dict["fontsize"] = str(font_size)
+        out_dict["fontsize"] = f'"{str(font_size)}!"'
         out_dict["height"] = str(qubit_size * px)
         out_dict["fixedsize"] = "True"
         out_dict["fontname"] = '"DejaVu Sans"'
@@ -1093,9 +1102,22 @@ def color_edge(edge):
         }
         return out_dict
 
+    graph_attributes = None
+    if not qubit_coordinates:
+        if planar:
+            graph_attributes = {
+                "overlap_scaling": "-7",
+                "overlap": "prism",
+                "model": "subset",
+            }
+        else:
+            graph_attributes = {
+                "overlap": "true",
+            }
     plot = graphviz_draw(
         graph,
         method="neato",
+        graph_attr=graph_attributes,
         node_attr_fn=color_node,
         edge_attr_fn=color_edge,
         filename=filename,

diff --git a/releasenotes/notes/adjust-neato-settings-3adcc0ae9e245ce9.yaml b/releasenotes/notes/adjust-neato-settings-3adcc0ae9e245ce9.yaml
@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    Fixes an issue with the visualizations of some backends/coupling maps that showed as folded on their own. The
+    `default ``neato`` setting <https://graphviz.org/docs/layouts/neato/>`_ works well in most cases. However,
+    ``prism`` overlap returns a more regular layout for other scenarios.
diff --git a/test/visual/mpl/graph/references/16_qubit_gate_map.png b/test/visual/mpl/graph/references/16_qubit_gate_map.png
diff --git a/test/visual/mpl/graph/references/27_qubit_gate_map.png b/test/visual/mpl/graph/references/27_qubit_gate_map.png
diff --git a/test/visual/mpl/graph/references/5_qubit_gate_map.png b/test/visual/mpl/graph/references/5_qubit_gate_map.png
diff --git a/test/visual/mpl/graph/references/65_qubit_gate_map.png b/test/visual/mpl/graph/references/65_qubit_gate_map.png
diff --git a/test/visual/mpl/graph/references/7_qubit_gate_map.png b/test/visual/mpl/graph/references/7_qubit_gate_map.png
diff --git a/test/visual/mpl/graph/references/bloch_multivector.png b/test/visual/mpl/graph/references/bloch_multivector.png
diff --git a/test/visual/mpl/graph/references/bloch_multivector_figsize_improvements.png b/test/visual/mpl/graph/references/bloch_multivector_figsize_improvements.png
diff --git a/test/visual/mpl/graph/references/figsize.png b/test/visual/mpl/graph/references/figsize.png
diff --git a/test/visual/mpl/graph/references/font_color.png b/test/visual/mpl/graph/references/font_color.png
diff --git a/test/visual/mpl/graph/references/hinton.png b/test/visual/mpl/graph/references/hinton.png
diff --git a/test/visual/mpl/graph/references/histogram.png b/test/visual/mpl/graph/references/histogram.png
diff --git a/test/visual/mpl/graph/references/histogram_2_sets_with_rest.png b/test/visual/mpl/graph/references/histogram_2_sets_with_rest.png
diff --git a/test/visual/mpl/graph/references/histogram_color.png b/test/visual/mpl/graph/references/histogram_color.png
diff --git a/test/visual/mpl/graph/references/histogram_desc_value_sort.png b/test/visual/mpl/graph/references/histogram_desc_value_sort.png
diff --git a/test/visual/mpl/graph/references/histogram_hamming.png b/test/visual/mpl/graph/references/histogram_hamming.png
diff --git a/test/visual/mpl/graph/references/histogram_legend.png b/test/visual/mpl/graph/references/histogram_legend.png
diff --git a/test/visual/mpl/graph/references/histogram_multiple_colors.png b/test/visual/mpl/graph/references/histogram_multiple_colors.png
diff --git a/test/visual/mpl/graph/references/histogram_title.png b/test/visual/mpl/graph/references/histogram_title.png
diff --git a/test/visual/mpl/graph/references/histogram_value_sort.png b/test/visual/mpl/graph/references/histogram_value_sort.png
diff --git a/test/visual/mpl/graph/references/histogram_with_rest.png b/test/visual/mpl/graph/references/histogram_with_rest.png
diff --git a/test/visual/mpl/graph/references/line_color.png b/test/visual/mpl/graph/references/line_color.png
diff --git a/test/visual/mpl/graph/references/paulivec.png b/test/visual/mpl/graph/references/paulivec.png
diff --git a/test/visual/mpl/graph/references/qsphere.png b/test/visual/mpl/graph/references/qsphere.png
diff --git a/test/visual/mpl/graph/references/qubit_color.png b/test/visual/mpl/graph/references/qubit_color.png
diff --git a/test/visual/mpl/graph/references/qubit_labels.png b/test/visual/mpl/graph/references/qubit_labels.png
diff --git a/test/visual/mpl/graph/references/qubit_size.png b/test/visual/mpl/graph/references/qubit_size.png
diff --git a/test/visual/mpl/graph/references/state_city.png b/test/visual/mpl/graph/references/state_city.png
diff --git a/test/visual/mpl/graph/test_graph_matplotlib_drawer.py b/test/visual/mpl/graph/test_graph_matplotlib_drawer.py
@@ -113,7 +113,7 @@ def test_plot_bloch_multivector(self):
             FAILURE_DIFF_DIR,
             FAILURE_PREFIX,
         )
-        self.assertGreaterEqual(ratio, 0.99)
+        self.assertGreaterEqual(ratio, 0.99, msg=fname)
 
     def test_plot_state_hinton(self):
         """test plot_state_hinton"""
@@ -437,7 +437,7 @@ def test_plot_7_qubit_gate_map(self):
             FAILURE_DIFF_DIR,
             FAILURE_PREFIX,
         )
-        self.assertGreaterEqual(ratio, 0.99)
+        self.assertGreaterEqual(ratio, 0.99, msg=fname)
 
     def test_plot_16_qubit_gate_map(self):
         """Test plot_gate_map using 16 qubit backend"""
@@ -455,7 +455,7 @@ def test_plot_16_qubit_gate_map(self):
             FAILURE_DIFF_DIR,
             FAILURE_PREFIX,
         )
-        self.assertGreaterEqual(ratio, 0.99)
+        self.assertGreaterEqual(ratio, 0.99, msg=fname)
 
     def test_plot_27_qubit_gate_map(self):
         """Test plot_gate_map using 27 qubit backend"""
@@ -527,7 +527,7 @@ def test_qubit_size(self):
             FAILURE_DIFF_DIR,
             FAILURE_PREFIX,
         )
-        self.assertGreaterEqual(ratio, 0.99)
+        self.assertGreaterEqual(ratio, 0.99, msg=fname)
 
     def test_qubit_color(self):
         """Test qubit_color parameter of plot_gate_map"""
@@ -545,7 +545,7 @@ def test_qubit_color(self):
             FAILURE_DIFF_DIR,
             FAILURE_PREFIX,
         )
-        self.assertGreaterEqual(ratio, 0.99)
+        self.assertGreaterEqual(ratio, 0.99, msg=fname)
 
     def test_qubit_labels(self):
         """Test qubit_labels parameter of plot_gate_map"""
@@ -658,7 +658,7 @@ def test_plot_bloch_multivector_figsize_improvements(self):
             FAILURE_DIFF_DIR,
             FAILURE_PREFIX,
         )
-        self.assertGreaterEqual(ratio, 0.99)
+        self.assertGreaterEqual(ratio, 0.99, msg=fname)
 
 
 if __name__ == "__main__":