Improves rendering of complex LaTeX expressions as long_names when plotting

xarray/plot/utils.py

@@ -490,7 +490,13 @@ def _get_units_from_attrs(da):
     else:
         units = _get_units_from_attrs(da)
 
-    return "\n".join(textwrap.wrap(name + extra + units, 30))
+    # Treat `name` differently if it's a latex sequence
+    if name.startswith("$") and (name.count("$") % 2 == 0):
+        return "$\n$".join(textwrap.wrap(
+            name + extra + units, 60, break_long_words=False)
+        )
+    else:
+        return "\n".join(textwrap.wrap(name + extra + units, 30))
 
 
 def _interval_to_mid_points(array):

xarray/tests/test_plot.py

@@ -2950,3 +2950,12 @@ def test_datarray_scatter(x, y, z, hue, markersize, row, col, add_legend, add_co
             add_legend=add_legend,
             add_colorbar=add_colorbar,
         )
+
+
+
+def test_latex_name_isnt_split():
+    da = xarray.DataArray()
+    long_latex_name = r"$Ra_s = \mathrm{mean}(\epsilon_k) / \mu M^2_\infty$"
+    da.attrs = dict(long_name = long_latex_name)
+    assert label_from_attrs(da) == long_latex_name
+

xarray/tests/test_utils.py

@@ -42,6 +42,7 @@ def test_safe_cast_to_index():
         assert expected.dtype == actual.dtype
 
 
+
 @pytest.mark.parametrize(
     "a, b, expected", [["a", "b", np.array(["a", "b"])], [1, 2, pd.Index([1, 2])]]
 )