From 1ca7240ab912d6a6c553f843ac8daaeb403f359b Mon Sep 17 00:00:00 2001
From: Antony Lee <anntzer.lee@gmail.com>
Date: Thu, 20 Apr 2023 10:54:27 +0200
Subject: [PATCH] Cleanup GridHelperCurveLinear/GridFinder.

- GridHelperCurveLinear: numpydocify; remove unused _aux_trans attribute.
- GridFinder: This class is used nowhere else but as attribute on
  GridHelperCurveLinear and could probably be inlined into it; for now,
  remove the duplicated constructor docstring.
---
 lib/mpl_toolkits/axisartist/grid_finder.py    | 13 ++++-----
 .../axisartist/grid_helper_curvelinear.py     | 27 ++++++++++++-------
 2 files changed, 23 insertions(+), 17 deletions(-)

diff --git a/lib/mpl_toolkits/axisartist/grid_finder.py b/lib/mpl_toolkits/axisartist/grid_finder.py
index 4468eb65f3e7..f969b011c4cd 100644
--- a/lib/mpl_toolkits/axisartist/grid_finder.py
+++ b/lib/mpl_toolkits/axisartist/grid_finder.py
@@ -121,6 +121,11 @@ def inverted(self):
 
 
 class GridFinder:
+    """
+    Internal helper for `~.grid_helper_curvelinear.GridHelperCurveLinear`, with
+    the same constructor parameters; should not be directly instantiated.
+    """
+
     def __init__(self,
                  transform,
                  extreme_finder=None,
@@ -128,14 +133,6 @@ def __init__(self,
                  grid_locator2=None,
                  tick_formatter1=None,
                  tick_formatter2=None):
-        """
-        transform : transform from the image coordinate (which will be
-        the transData of the axes to the world coordinate).
-
-        or transform = (transform_xy, inv_transform_xy)
-
-        locator1, locator2 : grid locator for 1st and 2nd axis.
-        """
         if extreme_finder is None:
             extreme_finder = ExtremeFinderSimple(20, 20)
         if grid_locator1 is None:
diff --git a/lib/mpl_toolkits/axisartist/grid_helper_curvelinear.py b/lib/mpl_toolkits/axisartist/grid_helper_curvelinear.py
index e5ba2c824257..da705704604a 100644
--- a/lib/mpl_toolkits/axisartist/grid_helper_curvelinear.py
+++ b/lib/mpl_toolkits/axisartist/grid_helper_curvelinear.py
@@ -234,18 +234,27 @@ def __init__(self, aux_trans,
                  tick_formatter1=None,
                  tick_formatter2=None):
         """
-        aux_trans : a transform from the source (curved) coordinate to
-        target (rectilinear) coordinate. An instance of MPL's Transform
-        (inverse transform should be defined) or a tuple of two callable
-        objects which defines the transform and its inverse. The callables
-        need take two arguments of array of source coordinates and
-        should return two target coordinates.
-
-        e.g., ``x2, y2 = trans(x1, y1)``
+        Parameters
+        ----------
+        aux_trans : `.Transform` or tuple[Callable, Callable]
+            The transform from curved coordinates to rectilinear coordinate:
+            either a `.Transform` instance (which provides also its inverse),
+            or a pair of callables ``(trans, inv_trans)`` that define the
+            transform and its inverse.  The callables should have signature::
+
+                x_rect, y_rect = trans(x_curved, y_curved)
+                x_curved, y_curved = inv_trans(x_rect, y_rect)
+
+        extreme_finder
+
+        grid_locator1, grid_locator2
+            Grid locators for each axis.
+
+        tick_formatter1, tick_formatter2
+            Tick formatters for each axis.
         """
         super().__init__()
         self._grid_info = None
-        self._aux_trans = aux_trans
         self.grid_finder = GridFinder(aux_trans,
                                       extreme_finder,
                                       grid_locator1,