Handle NaN in bar labels and error bars

oscargus · oscargus · commit 3a195da19473 · 2022-04-28T23:26:06.000+02:00
diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
@@ -2674,7 +2674,7 @@ def sign(x):
                 extrema = max(x0, x1) if dat >= 0 else min(x0, x1)
                 length = abs(x0 - x1)
 
-            if err is None:
+            if err is None or np.size(err) == 0:
                 endpt = extrema
             elif orientation == "vertical":
                 endpt = err[:, 1].max() if dat >= 0 else err[:, 1].min()
@@ -3504,6 +3504,9 @@ def apply_mask(arrays, mask): return [array[mask] for array in arrays]
                     f"'{dep_axis}err' (shape: {np.shape(err)}) must be a "
                     f"scalar or a 1D or (2, n) array-like whose shape matches "
                     f"'{dep_axis}' (shape: {np.shape(dep)})") from None
+            if any(e != e for e in err.ravel()):
+                raise ValueError(
+                    f"'{dep_axis}err' must not contain NaN values")
             if np.any(err < -err):  # like err<0, but also works for timedelta.
                 raise ValueError(
                     f"'{dep_axis}err' must not contain negative values")
diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
@@ -7549,6 +7549,19 @@ def test_bar_label_nan_ydata_inverted():
     assert labels[0].get_va() == 'bottom'
 
 
+def test_nan_barlabels():
+    ax = plt.gca()
+    bars = ax.bar([2, 3], [np.nan, 1], yerr=[0.3, 0.5])
+    labels = ax.bar_label(bars)
+    assert [l.get_text() for l in labels] == ['', '1']
+
+    with pytest.raises(ValueError,
+                       match="'yerr' must not contain NaN values"):
+        ax = plt.gca()
+        bars = ax.bar([2, 3], [np.nan, 1], yerr=[np.nan, 0.5])
+        labels = ax.bar_label(bars)
+
+
 def test_patch_bounds():  # PR 19078
     fig, ax = plt.subplots()
     ax.add_patch(mpatches.Wedge((0, -1), 1.05, 60, 120, 0.1))
