Merge pull request matplotlib#15195 from anntzer/quiver3d-int

Fix integers being passed as length to quiver3d.

Author: timhoffm

lib/mpl_toolkits/mplot3d/axes3d.py

@@ -2607,14 +2607,14 @@ def calc_arrow(uvw, angle=15):
             self.add_collection(linec)
             return linec
 
-        shaft_dt = np.array([0, length])
+        shaft_dt = np.array([0., length], dtype=float)
         arrow_dt = shaft_dt * arrow_length_ratio
 
         cbook._check_in_list(['tail', 'middle', 'tip'], pivot=pivot)
         if pivot == 'tail':
             shaft_dt -= length
         elif pivot == 'middle':
-            shaft_dt -= length/2.
+            shaft_dt -= length / 2
 
         XYZ = np.column_stack(input_args[:3])
         UVW = np.column_stack(input_args[3:argi]).astype(float)

lib/mpl_toolkits/tests/test_mplot3d.py

@@ -970,3 +970,19 @@ def get_formatters(ax, names):
         for fmt in get_formatters(row[4], names):
             fmt.set_useMathText(
                 not mpl.rcParams["axes.formatter.use_mathtext"])
+
+
+@check_figures_equal(extensions=["png"])
+def test_quiver3D_smoke(fig_test, fig_ref):
+    pivot = "middle"
+    # Make the grid
+    x, y, z = np.meshgrid(
+        np.arange(-0.8, 1, 0.2),
+        np.arange(-0.8, 1, 0.2),
+        np.arange(-0.8, 1, 0.8)
+    )
+    u = v = w = np.ones_like(x)
+
+    for fig, length in zip((fig_ref, fig_test), (1, 1.0)):
+        ax = fig.gca(projection="3d")
+        ax.quiver(x, y, z, u, v, w, length=length, pivot=pivot)