Fix MatPlot.clear() crash with matplotlib 3.11+#229
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Pass clear=True to plt.subplots() in _init_plot so that reusing a figure number (as done in MatPlot.clear()) no longer raises a ValueError in matplotlib >= 3.11.
Copilot
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Fix matplotlib clear() ValueError with matplotlib 3.11+
Fix MatPlot.clear() crash with matplotlib 3.11+
Jun 16, 2026
Copilot created this pull request from a session on behalf of
jenshnielsen
June 16, 2026 06:50
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matplotlib 3.11 added a guard in
plt.subplots()that raisesValueErrorwhen called with an already-existing figure number unlessclear=Trueis passed.MatPlot.clear()triggered this by calling_init_plot(..., num=self.fig.number)afterfig.clf()— the figure remains registered even after being cleared.Change
qcmatplotlib.py: passclear=Trueto bothplt.subplots()calls in_init_plot(), eliminating theValueError: Figure {num!r} already existserror onMatPlot.clear().