Set 1D plots to put the coordinate on the y-axis where appropriate.

Author: trexfeathers

lib/iris/plot.py

@@ -665,7 +665,20 @@ def _get_plot_objects(args):
         # single argument
         v_object = args[0]
         u_object = _u_object_from_v_object(v_object)
+
         u, v = _uv_from_u_object_v_object(u_object, args[0])
+
+        # If a single cube argument, and the associated dimension coordinate
+        # is vertical-like, put the coordinate on the y axis, and the data o
+        # the x.
+        if isinstance(v_object, iris.cube.Cube) and iris.util.guess_coord_axis(
+            u_object
+        ) in ["Y", "Z"]:
+            # If we have a single argument, and it is vertical-like, put it on
+            # the y axis.
+            u_object, v_object = v_object, u_object
+            u, v = v, u
+
         args = args[1:]
     return u_object, v_object, u, v, args
 

lib/iris/quickplot.py

@@ -138,12 +138,8 @@ def _get_titles(u_object, v_object):
 
 
 def _label_1d_plot(*args, **kwargs):
-    if len(args) > 1 and isinstance(
-        args[1], (iris.cube.Cube, iris.coords.Coord)
-    ):
-        xlabel, ylabel, title = _get_titles(*args[:2])
-    else:
-        xlabel, ylabel, title = _get_titles(None, args[0])
+    u_obj, v_obj, _, _, _ = iplt._get_plot_objects(args)
+    xlabel, ylabel, title = _get_titles(u_obj, v_obj)
 
     axes = kwargs.pop("axes", None)
 

lib/iris/tests/unit/quickplot/test_plot.py

@@ -8,6 +8,7 @@
 # Import iris.tests first so that some things can be initialised before
 # importing anything else.
 import iris.tests as tests
+from iris.tests.stock import simple_2d
 from iris.tests.unit.plot import TestGraphicStringCoord
 
 if tests.MPL_AVAILABLE:
@@ -29,5 +30,29 @@ def test_xaxis_labels(self):
         self.assertBoundsTickLabels("xaxis")
 
 
+class TestAxisLabels(tests.GraphicsTest):
+    def test_xy_cube(self):
+        c = simple_2d()[:, 0]
+        qplt.plot(c)
+        ax = qplt.plt.gca()
+        x = ax.xaxis.get_label().get_text()
+        self.assertEqual(x, "Bar")
+        y = ax.yaxis.get_label().get_text()
+        self.assertEqual(y, "Thingness")
+
+    def test_yx_cube(self):
+        c = simple_2d()[:, 0]
+        c.transpose()
+        # Making the cube a vertical coordinate should change the default
+        # orientation of the plot.
+        c.coord("bar").attributes["positive"] = "up"
+        qplt.plot(c)
+        ax = qplt.plt.gca()
+        x = ax.xaxis.get_label().get_text()
+        self.assertEqual(x, "Thingness")
+        y = ax.yaxis.get_label().get_text()
+        self.assertEqual(y, "Bar")
+
+
 if __name__ == "__main__":
     tests.main()