Added support for empty input to scatter3d and plot3d.

Author: WeatherGod

lib/mpl_toolkits/mplot3d/art3d.py

@@ -319,7 +319,10 @@ def do_3d_projection(self, renderer):
         self.set_edgecolors(zalpha(self._edgecolor3d, vzs))
         PatchCollection.set_offsets(self, zip(vxs, vys))
 
-        return min(vzs)
+        if vzs.size > 0 :
+            return min(vzs)
+        else :
+            return np.nan
 
     def draw(self, renderer):
         self._old_draw(renderer)
@@ -461,8 +464,10 @@ def do_3d_projection(self, renderer):
            zvec = np.array([[0], [0], [self._sort_zpos], [1]])
            ztrans = proj3d.proj_transform_vec(zvec, renderer.M)
            return ztrans[2][0]
-        else:
-            return np.min(tzs)
+        elif tzs.size > 0 :
+            return self._zsortfunc(tzs)
+        else :
+            return np.nan
 
     def set_facecolor(self, colors):
         PolyCollection.set_facecolor(self, colors)
@@ -559,8 +564,9 @@ def get_colors(c, num):
 def zalpha(colors, zs):
     """Modify the alphas of the color list according to depth"""
     colors = get_colors(colors, len(zs))
-    norm = Normalize(min(zs), max(zs))
-    sats = 1 - norm(zs) * 0.7
-    colors = [(c[0], c[1], c[2], c[3] * s) for c, s in zip(colors, sats)]
+    if zs.size > 0 :
+        norm = Normalize(min(zs), max(zs))
+        sats = 1 - norm(zs) * 0.7
+        colors = [(c[0], c[1], c[2], c[3] * s) for c, s in zip(colors, sats)]
     return colors
 

lib/mpl_toolkits/mplot3d/axes3d.py

@@ -670,17 +670,29 @@ def plot(self, xs, ys, *args, **kwargs):
         Other arguments are passed on to
         :func:`~matplotlib.axes.Axes.plot`
         '''
-
+        # FIXME: This argument parsing might be better handled
+        #        when we set later versions of python for
+        #        minimum requirements.  Currently at 2.4.
+        #        Note that some of the reason for the current difficulty
+        #        is caused by the fact that we want to insert a new
+        #        (semi-optional) positional argument 'Z' right before
+        #        many other traditional positional arguments occur
+        #        such as the color, linestyle and/or marker.
         had_data = self.has_data()
         zs = kwargs.pop('zs', 0)
         zdir = kwargs.pop('zdir', 'z')
 
         argsi = 0
         # First argument is array of zs
         if len(args) > 0 and cbook.iterable(args[0]) and \
-                len(xs) == len(args[0]) and cbook.is_scalar(args[0][0]):
-            zs = args[argsi]
-            argsi += 1
+                len(xs) == len(args[0]) :
+            # So, we know that it is an array with
+            # first dimension the same as xs.
+            # Next, check to see if the data contained
+            # therein (if any) is scalar (and not another array).
+            if len(args[0]) == 0 or cbook.is_scalar(args[0][0]) :
+                zs = args[argsi]
+                argsi += 1
 
         # First argument is z value
         elif len(args) > 0 and cbook.is_scalar(args[0]):