Merge pull request matplotlib#4019 from myshen/annot_neg_coords

    BUG : fix negative coords in annotation

Author: tacaswell

lib/matplotlib/tests/baseline_images/test_text/annotation_negative_coords.png

@@ -279,8 +279,26 @@ def test_get_rotation_mod360():
     for i, j in zip([360., 377., 720+177.2], [0., 17., 177.2]):
         assert_almost_equal(text.get_rotation(i), j)
 
+
 @image_comparison(baseline_images=['text_bboxclip'])
 def test_bbox_clipping():
     plt.text(0.9, 0.2, 'Is bbox clipped?', backgroundcolor='r', clip_on=True)
     t = plt.text(0.9, 0.5, 'Is fancy bbox clipped?', clip_on=True)
     t.set_bbox({"boxstyle": "round, pad=0.1"})
+
+
+@image_comparison(baseline_images=['annotation_negative_coords'],
+                  extensions=['png'])
+def test_annotation_negative_coords():
+    fig = plt.figure()
+    ax = plt.subplot(1, 1, 1)
+
+    ax.annotate("+fpt", (15, 40), xycoords="figure points")
+    ax.annotate("+fpx", (25, 30), xycoords="figure pixels")
+    ax.annotate("+apt", (35, 20), xycoords="axes points")
+    ax.annotate("+apx", (45, 10), xycoords="axes pixels")
+
+    ax.annotate("-fpt", (-55, -40), xycoords="figure points")
+    ax.annotate("-fpx", (-45, -30), xycoords="figure pixels")
+    ax.annotate("-apt", (-35, -20), xycoords="axes points")
+    ax.annotate("-apx", (-25, -10), xycoords="axes pixels")

lib/matplotlib/tests/test_text.py

@@ -1531,17 +1531,17 @@ def _get_xy(self, renderer, x, y, s):
         if s2 == 'data':
             y = float(self.convert_yunits(y))
 
-        tr = self._get_xy_transform(renderer, s)
+        tr = self._get_xy_transform(renderer, (x, y), s)
         x1, y1 = tr.transform_point((x, y))
         return x1, y1
 
-    def _get_xy_transform(self, renderer, s):
+    def _get_xy_transform(self, renderer, xy, s):
 
         if isinstance(s, tuple):
             s1, s2 = s
             from matplotlib.transforms import blended_transform_factory
-            tr1 = self._get_xy_transform(renderer, s1)
-            tr2 = self._get_xy_transform(renderer, s2)
+            tr1 = self._get_xy_transform(renderer, xy, s1)
+            tr2 = self._get_xy_transform(renderer, xy, s2)
             tr = blended_transform_factory(tr1, tr2)
             return tr
 
@@ -1590,7 +1590,17 @@ def _get_xy_transform(self, renderer, s):
         #     bbox0 = self._get_bbox(renderer, bbox)
 
         if bbox0 is not None:
-            xy0 = bbox0.bounds[:2]
+            x, y = xy
+            bounds = bbox0.extents
+            if x < 0:
+                x0 = bounds[2]
+            else:
+                x0 = bounds[0]
+            if y < 0:
+                y0 = bounds[3]
+            else:
+                y0 = bounds[1]
+            xy0 = (x0, y0)
         elif bbox_name == "offset":
             xy0 = self._get_ref_xy(renderer)
 
@@ -1950,7 +1960,8 @@ def _update_position_xytext(self, renderer, xy_pixel):
         patch.
         """
         # generate transformation,
-        self.set_transform(self._get_xy_transform(renderer, self.anncoords))
+        self.set_transform(self._get_xy_transform(
+            renderer, self.xy, self.anncoords))
 
         ox0, oy0 = self._get_xy_display()
         ox1, oy1 = xy_pixel