doc: Provide better odcumentation when ndiv is set to auto

Vladimir · Vladimir · commit e799a1df2115 · 2020-10-15T00:00:40.000+02:00
diff --git a/lib/matplotlib/ticker.py b/lib/matplotlib/ticker.py
@@ -2885,7 +2885,10 @@ def __init__(self, n=None):
         between major ticks.
 
         If *n* is omitted or None, the value stored in rcParams will be used.
-        In case *n* is set to 'auto', it will be set to 4 or 5.
+        In case *n* is set to 'auto', it will be set to 4 or 5. If the distance
+        between the major ticks equals 1, 2.5, 5 or 10 it can be perfectly
+        divided in 5 equidistant sub-intervals with a length multiple of
+        0.05. Otherwise it is divided in 4 sub-intervals.
         """
         self.ndivs = n
 
