Backport PR #23333: Fix errorbar handling of nan.

tacaswell · tacaswell · commit 82a60d8ac7ef · 2022-06-24T18:12:04.000-04:00
Merge pull request #23333 from anntzer/en Fix errorbar handling of nan. (cherry picked from commit a2ad1f7) Conflicts: lib/matplotlib/axes/_axes.py Other min -> manmin type changes on main
diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
@@ -1060,13 +1060,14 @@ def hlines(self, y, xmin, xmax, colors=None, linestyles='solid',
         lines.update(kwargs)
 
         if len(y) > 0:
-            minx = min(xmin.min(), xmax.min())
-            maxx = max(xmin.max(), xmax.max())
-            miny = y.min()
-            maxy = y.max()
-
+            # Extreme values of xmin/xmax/y.  Using masked_verts here handles
+            # the case of y being a masked *object* array (as can be generated
+            # e.g. by errorbar()), which would make nanmin/nanmax stumble.
+            minx = np.nanmin(masked_verts[..., 0])
+            maxx = np.nanmax(masked_verts[..., 0])
+            miny = np.nanmin(masked_verts[..., 1])
+            maxy = np.nanmax(masked_verts[..., 1])
             corners = (minx, miny), (maxx, maxy)
-
             self.update_datalim(corners)
             self._request_autoscale_view()
 
@@ -1139,11 +1140,13 @@ def vlines(self, x, ymin, ymax, colors=None, linestyles='solid',
         lines.update(kwargs)
 
         if len(x) > 0:
-            minx = x.min()
-            maxx = x.max()
-            miny = min(ymin.min(), ymax.min())
-            maxy = max(ymin.max(), ymax.max())
-
+            # Extreme values of x/ymin/ymax.  Using masked_verts here handles
+            # the case of x being a masked *object* array (as can be generated
+            # e.g. by errorbar()), which would make nanmin/nanmax stumble.
+            minx = np.nanmin(masked_verts[..., 0])
+            maxx = np.nanmax(masked_verts[..., 0])
+            miny = np.nanmin(masked_verts[..., 1])
+            maxy = np.nanmax(masked_verts[..., 1])
             corners = (minx, miny), (maxx, maxy)
             self.update_datalim(corners)
             self._request_autoscale_view()
diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
@@ -3633,6 +3633,20 @@ def test_errorbar_linewidth_type(elinewidth):
     plt.errorbar([1, 2, 3], [1, 2, 3], yerr=[1, 2, 3], elinewidth=elinewidth)
 
 
+@check_figures_equal(extensions=["png"])
+def test_errorbar_nan(fig_test, fig_ref):
+    ax = fig_test.add_subplot()
+    xs = range(5)
+    ys = np.array([1, 2, np.nan, np.nan, 3])
+    es = np.array([4, 5, np.nan, np.nan, 6])
+    ax.errorbar(xs, ys, es)
+    ax = fig_ref.add_subplot()
+    ys = np.array([1, 2, np.nan, np.nan, 3])
+    es = np.array([4, 5, np.nan, np.nan, 6])
+    ax.errorbar([0, 1], [1, 2], [4, 5])
+    ax.errorbar([4], [3], [6], fmt="C0")
+
+
 @image_comparison(['hist_stacked_stepfilled', 'hist_stacked_stepfilled'])
 def test_hist_stacked_stepfilled():
     # make some data
