Merge pull request #20241 from meeseeksmachine/auto-backport-of-pr-20212-on-v3.4.x

timhoffm · web-flow · commit 86acc0c0295a · 2021-05-16T16:31:43.000+02:00
Backport PR #20212 on branch v3.4.x (Update span_selector.py)
diff --git a/examples/widgets/span_selector.py b/examples/widgets/span_selector.py
@@ -32,10 +32,12 @@ def onselect(xmin, xmax):
 
     region_x = x[indmin:indmax]
     region_y = y[indmin:indmax]
-    line2.set_data(region_x, region_y)
-    ax2.set_xlim(region_x[0], region_x[-1])
-    ax2.set_ylim(region_y.min(), region_y.max())
-    fig.canvas.draw()
+
+    if len(region_x) >= 2:
+        line2.set_data(region_x, region_y)
+        ax2.set_xlim(region_x[0], region_x[-1])
+        ax2.set_ylim(region_y.min(), region_y.max())
+        fig.canvas.draw()
 
 #############################################################################
 # .. note::
