Backport PR matplotlib#29167: BUGFIX: use axes unit information in Co…

…nnectionPatch

lib/matplotlib/category.py

@@ -17,7 +17,7 @@
 
 import numpy as np
 
-from matplotlib import _api, ticker, units
+from matplotlib import _api, cbook, ticker, units
 
 
 _log = logging.getLogger(__name__)
@@ -55,7 +55,8 @@ def convert(value, unit, axis):
         values = np.atleast_1d(np.array(value, dtype=object))
         # force an update so it also does type checking
         unit.update(values)
-        return np.vectorize(unit._mapping.__getitem__, otypes=[float])(values)
+        s = np.vectorize(unit._mapping.__getitem__, otypes=[float])(values)
+        return s if not cbook.is_scalar_or_string(value) else s[0]
 
     @staticmethod
     def axisinfo(unit, axis):

lib/matplotlib/patches.py

@@ -4589,23 +4589,27 @@ def _get_xy(self, xy, s, axes=None):
         s0 = s  # For the error message, if needed.
         if axes is None:
             axes = self.axes
-        xy = np.array(xy)
+
+        # preserve mixed type input (such as str, int)
+        x = np.array(xy[0])
+        y = np.array(xy[1])
+
         fig = self.get_figure(root=False)
         if s in ["figure points", "axes points"]:
-            xy *= fig.dpi / 72
+            x = x * fig.dpi / 72
+            y = y * fig.dpi / 72
             s = s.replace("points", "pixels")
         elif s == "figure fraction":
             s = fig.transFigure
         elif s == "subfigure fraction":
             s = fig.transSubfigure
         elif s == "axes fraction":
             s = axes.transAxes
-        x, y = xy
 
         if s == 'data':
             trans = axes.transData
-            x = float(self.convert_xunits(x))
-            y = float(self.convert_yunits(y))
+            x = cbook._to_unmasked_float_array(axes.xaxis.convert_units(x))
+            y = cbook._to_unmasked_float_array(axes.yaxis.convert_units(y))
             return trans.transform((x, y))
         elif s == 'offset points':
             if self.xycoords == 'offset points':  # prevent recursion

lib/matplotlib/tests/test_patches.py

@@ -606,6 +606,28 @@ def test_connection_patch_fig(fig_test, fig_ref):
     fig_ref.add_artist(con)
 
 
+@check_figures_equal(extensions=["png"])
+def test_connection_patch_pixel_points(fig_test, fig_ref):
+    xyA_pts = (.3, .2)
+    xyB_pts = (-30, -20)
+
+    ax1, ax2 = fig_test.subplots(1, 2)
+    con = mpatches.ConnectionPatch(xyA=xyA_pts, coordsA="axes points", axesA=ax1,
+                                   xyB=xyB_pts, coordsB="figure points",
+                                   arrowstyle="->", shrinkB=5)
+    fig_test.add_artist(con)
+
+    plt.rcParams["savefig.dpi"] = plt.rcParams["figure.dpi"]
+
+    ax1, ax2 = fig_ref.subplots(1, 2)
+    xyA_pix = (xyA_pts[0]*(fig_ref.dpi/72), xyA_pts[1]*(fig_ref.dpi/72))
+    xyB_pix = (xyB_pts[0]*(fig_ref.dpi/72), xyB_pts[1]*(fig_ref.dpi/72))
+    con = mpatches.ConnectionPatch(xyA=xyA_pix, coordsA="axes pixels", axesA=ax1,
+                                   xyB=xyB_pix, coordsB="figure pixels",
+                                   arrowstyle="->", shrinkB=5)
+    fig_ref.add_artist(con)
+
+
 def test_datetime_rectangle():
     # Check that creating a rectangle with timedeltas doesn't fail
     from datetime import datetime, timedelta

lib/matplotlib/tests/test_units.py

@@ -4,6 +4,7 @@
 
 import matplotlib.pyplot as plt
 from matplotlib.testing.decorators import check_figures_equal, image_comparison
+import matplotlib.patches as mpatches
 import matplotlib.units as munits
 from matplotlib.category import StrCategoryConverter, UnitData
 from matplotlib.dates import DateConverter
@@ -336,3 +337,17 @@ def test_plot_kernel():
     # just a smoketest that fail
     kernel = Kernel([1, 2, 3, 4, 5])
     plt.plot(kernel)
+
+
+def test_connection_patch_units(pd):
+    # tests that this doesn't raise an error
+    fig, (ax1, ax2) = plt.subplots(nrows=2, figsize=(10, 5))
+    x = pd.Timestamp('2017-01-01T12')
+    ax1.axvline(x)
+    y = "test test"
+    ax2.axhline(y)
+    arr = mpatches.ConnectionPatch((x, 0), (0, y),
+                                   coordsA='data', coordsB='data',
+                                   axesA=ax1, axesB=ax2)
+    fig.add_artist(arr)
+    fig.draw_without_rendering()