From 87bab66cb54c456014407a779188bc844f5d1b84 Mon Sep 17 00:00:00 2001
From: Antony Lee <anntzer.lee@gmail.com>
Date: Tue, 20 Apr 2021 13:55:42 +0200
Subject: [PATCH] Simplify _redo_transform_rel_fig.

- width_ratios and height_ratios are never None (None gets normalized to
  [1, 1, ...] in the setters).
- We don't need to separately handle the `is_first_row()/is_last_col()`
  cases (the sums will evaluate to 0/1 as needed).
- Naming the width/height dx/dy makes everything line up neatly.
---
 lib/matplotlib/figure.py | 37 +++++++++----------------------------
 1 file changed, 9 insertions(+), 28 deletions(-)

diff --git a/lib/matplotlib/figure.py b/lib/matplotlib/figure.py
index d29a9d964cd1..a0c7c4e44fe7 100644
--- a/lib/matplotlib/figure.py
+++ b/lib/matplotlib/figure.py
@@ -2011,42 +2011,23 @@ def _redo_transform_rel_fig(self, bbox=None):
             If not None, then the bbox is used for relative bounding box.
             Otherwise it is calculated from the subplotspec.
         """
-
         if bbox is not None:
             self.bbox_relative.p0 = bbox.p0
             self.bbox_relative.p1 = bbox.p1
             return
-
-        gs = self._subplotspec.get_gridspec()
         # need to figure out *where* this subplotspec is.
-        wr = gs.get_width_ratios()
-        hr = gs.get_height_ratios()
-        nrows, ncols = gs.get_geometry()
-        if wr is None:
-            wr = np.ones(ncols)
-        else:
-            wr = np.array(wr)
-        if hr is None:
-            hr = np.ones(nrows)
-        else:
-            hr = np.array(hr)
-        widthf = np.sum(wr[self._subplotspec.colspan]) / np.sum(wr)
-        heightf = np.sum(hr[self._subplotspec.rowspan]) / np.sum(hr)
-
-        x0 = 0
-        if not self._subplotspec.is_first_col():
-            x0 += np.sum(wr[:self._subplotspec.colspan.start]) / np.sum(wr)
-
-        y0 = 0
-        if not self._subplotspec.is_last_row():
-            y0 += 1 - (np.sum(hr[:self._subplotspec.rowspan.stop]) /
-                       np.sum(hr))
-
+        gs = self._subplotspec.get_gridspec()
+        wr = np.asarray(gs.get_width_ratios())
+        hr = np.asarray(gs.get_height_ratios())
+        dx = wr[self._subplotspec.colspan].sum() / wr.sum()
+        dy = hr[self._subplotspec.rowspan].sum() / hr.sum()
+        x0 = wr[:self._subplotspec.colspan.start].sum() / wr.sum()
+        y0 = 1 - hr[:self._subplotspec.rowspan.stop].sum() / hr.sum()
         if self.bbox_relative is None:
-            self.bbox_relative = Bbox.from_bounds(x0, y0, widthf, heightf)
+            self.bbox_relative = Bbox.from_bounds(x0, y0, dx, dy)
         else:
             self.bbox_relative.p0 = (x0, y0)
-            self.bbox_relative.p1 = (x0 + widthf, y0 + heightf)
+            self.bbox_relative.p1 = (x0 + dx, y0 + dy)
 
     def get_constrained_layout(self):
         """