From d324f1c119f7e3a32f1961e5500b80b2af9febba Mon Sep 17 00:00:00 2001
From: Eric Prestat <eric.prestat@gmail.com>
Date: Wed, 8 Dec 2021 22:28:18 +0000
Subject: [PATCH] Fix rotation for aspect ratio of the axes values different
 from 1

---
 lib/matplotlib/tests/test_widgets.py | 23 +++++++++++++++++++++++
 lib/matplotlib/widgets.py            |  5 +++--
 2 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/lib/matplotlib/tests/test_widgets.py b/lib/matplotlib/tests/test_widgets.py
index 1986cd23f160..7220e269060d 100644
--- a/lib/matplotlib/tests/test_widgets.py
+++ b/lib/matplotlib/tests/test_widgets.py
@@ -452,6 +452,29 @@ def onselect(epress, erelease):
             tool._selection_artist.rotation_point = 'unvalid_value'
 
 
+def test_rectangle_rotate_aspect_ratio():
+    _, ax = plt.subplots()
+    ax.plot([1, 2, 3], [10, 20, 30])
+
+    def onselect(epress, erelease):
+        pass
+
+    tool = widgets.RectangleSelector(ax, onselect=onselect, interactive=True)
+
+    # Draw rectangle
+    do_event(tool, 'press', xdata=1, ydata=10)
+    do_event(tool, 'onmove', xdata=1.5, ydata=14)
+    do_event(tool, 'release', xdata=1.5, ydata=14)
+    assert tool.extents == (1.0, 1.5, 10.0, 14.0)
+
+    # Rotate clockwise using bottom-right corner
+    do_event(tool, 'on_key_press', key='r')
+    do_event(tool, 'press', xdata=1.5, ydata=10)
+    do_event(tool, 'onmove', xdata=1.4, ydata=8.7)
+    do_event(tool, 'release', xdata=1.4, ydata=8.7)
+    assert_allclose(tool.rotation, -27.8, rtol=0.1)
+
+
 def test_rectange_add_remove_set():
     ax = get_ax()
 
diff --git a/lib/matplotlib/widgets.py b/lib/matplotlib/widgets.py
index 9c9fad1a20d5..69b33477b120 100644
--- a/lib/matplotlib/widgets.py
+++ b/lib/matplotlib/widgets.py
@@ -3087,8 +3087,9 @@ def _onmove(self, event):
             a = np.array([eventpress.xdata, eventpress.ydata])
             b = np.array(self.center)
             c = np.array([event.xdata, event.ydata])
-            angle = (np.arctan2(c[1]-b[1], c[0]-b[0]) -
-                     np.arctan2(a[1]-b[1], a[0]-b[0]))
+            ax_corr = self.ax._get_aspect_ratio()
+            angle = (np.arctan2((c[1]-b[1]) * ax_corr, c[0]-b[0]) -
+                     np.arctan2((a[1]-b[1]) * ax_corr, a[0]-b[0]))
             self.rotation = np.rad2deg(self._rotation_on_press + angle)
 
         # resize an existing shape