Merge pull request #16534 from pharshalp/maxnlocator_contourf_contour_doc

efiring · web-flow · commit 76c764c48b9f · 2020-03-02T09:14:28.000-10:00
DOC: MaxNLocator and contour/contourf doc update (replaces #16428)
diff --git a/lib/matplotlib/contour.py b/lib/matplotlib/contour.py
@@ -1612,8 +1612,10 @@ def _initialize_x_y(self, z):
         levels : int or array-like, optional
             Determines the number and positions of the contour lines / regions.
 
-            If an int *n*, use *n* data intervals; i.e. draw *n+1* contour
-            lines. The level heights are automatically chosen.
+            If an int *n*, use an algorithm
+            (see `~matplotlib.ticker.MaxNLocator`) that tries to provide
+            no more than *n+1* "nice" contour levels between vmin and vmax.
+            The level heights are automatically chosen.
 
             If array-like, draw contour lines at the specified levels.
             The values must be in increasing order.
diff --git a/lib/matplotlib/ticker.py b/lib/matplotlib/ticker.py
@@ -1945,7 +1945,8 @@ def ge(self, x):
 
 class MaxNLocator(Locator):
     """
-    Select no more than N intervals at nice locations.
+    Find nice tick locations with no more than N being within the view limits.
+    Locations beyond the limits are added to support autoscaling.
     """
     default_params = dict(nbins=10,
                           steps=None,
