Regenerate plot_gate_map_reference images

qiskit/visualization/state_visualization.py

@@ -702,7 +702,8 @@ def __init__(self, xs, ys, zs, *args, **kwargs):
         def draw(self, renderer):
             """Draw the arrow."""
             xs3d, ys3d, zs3d = self._verts3d
-            xs, ys, _ = proj3d.proj_transform(xs3d, ys3d, zs3d, renderer.M)
+            xs, ys, _ = proj3d.proj_transform(xs3d, ys3d, zs3d,
+                                              self.axes.M)
             self.set_positions((xs[0], ys[0]), (xs[1], ys[1]))
             FancyArrowPatch.draw(self, renderer)
 

test/python/visualization/test_gate_map.py

@@ -10,9 +10,12 @@
 # copyright notice, and modified files need to carry a notice indicating
 # that they have been altered from the originals.
 
+# pylint: disable=bad-docstring-quotes
+
 """A test for visualizing device coupling maps"""
 import unittest
 import os
+import sys
 
 from ddt import ddt, data
 from qiskit.test.mock import FakeProvider
@@ -27,6 +30,10 @@
     import matplotlib.pyplot as plt
 
 
+@unittest.skipIf(sys.version_info < (3, 7),
+                 'Skipping image comparison tests on python 3.6 as they '
+                 'depend on the local matlplotlib environment matching the '
+                 'environment for the reference images which is only >=3.7')
 @ddt
 class TestGateMap(QiskitVisualizationTestCase):
     """ visual tests for plot_gate_map """