diff --git a/holoviews/core/data/xarray.py b/holoviews/core/data/xarray.py
index b2f25a070c..51e6cda8c7 100644
--- a/holoviews/core/data/xarray.py
+++ b/holoviews/core/data/xarray.py
@@ -50,10 +50,11 @@ def shape(cls, dataset, gridded=False):
                      if kd.name in array.dims][::-1]
             if not all(d in names for d in array.dims):
                 array = np.squeeze(array)
-            try:
-                array = array.transpose(*names, transpose_coords=False)
-            except:
-                array = array.transpose(*names) # Handle old xarray
+            if len(names) > 1:
+                try:
+                    array = array.transpose(*names, transpose_coords=False)
+                except:
+                    array = array.transpose(*names) # Handle old xarray
         shape = array.shape
         if gridded:
             return shape
@@ -218,6 +219,10 @@ def range(cls, dataset, dimension):
         da = dask_array_module()
         if da and isinstance(dmin, da.Array):
             dmin, dmax = da.compute(dmin, dmax)
+        if isinstance(dmin, np.ndarray) and dmin.shape == ():
+            dmin = dmin[()]
+        if isinstance(dmax, np.ndarray) and dmax.shape == ():
+            dmax = dmax[()]
         dmin = dmin if np.isscalar(dmin) or isinstance(dmin, util.datetime_types) else dmin.item()
         dmax = dmax if np.isscalar(dmax) or isinstance(dmax, util.datetime_types) else dmax.item()
         return dmin, dmax
@@ -390,8 +395,10 @@ def ndloc(cls, dataset, indices):
         sampled = (all(isinstance(ind, np.ndarray) and ind.dtype.kind != 'b'
                        for ind in adjusted_indices) and len(indices) == len(kdims))
         if sampled or (all_scalar and len(indices) == len(kdims)):
+            import xarray as xr
             if all_scalar: isel = {k: [v] for k, v in isel.items()}
-            return dataset.data.isel_points(**isel).to_dataframe().reset_index()
+            selected = dataset.data.isel({k: xr.DataArray(v) for k, v in isel.items()})
+            return selected.to_dataframe().reset_index()
         else:
             return dataset.data.isel(**isel)
 
diff --git a/holoviews/plotting/util.py b/holoviews/plotting/util.py
index f72ded0ac7..f5966f4b81 100644
--- a/holoviews/plotting/util.py
+++ b/holoviews/plotting/util.py
@@ -522,6 +522,20 @@ def map_colors(arr, crange, cmap, hex=True):
         return arr
 
 
+def resample_palette(palette, ncolors, categorical, cmap_categorical):
+    """
+    Resample the number of colors in a palette to the selected number.
+    """
+    if len(palette) != ncolors:
+        if categorical and cmap_categorical:
+            palette = [palette[i%len(palette)] for i in range(ncolors)]
+        else:
+            lpad, rpad = -0.5, 0.49999999999
+            indexes = np.linspace(lpad, (len(palette)-1)+rpad, ncolors)
+            palette = [palette[int(np.round(v))] for v in indexes]
+    return palette
+
+
 def mplcmap_to_palette(cmap, ncolors=None, categorical=False):
     """
     Converts a matplotlib colormap to palette of RGB hex strings."
@@ -550,6 +564,22 @@ def mplcmap_to_palette(cmap, ncolors=None, categorical=False):
     return [rgb2hex(c) for c in cmap(np.linspace(0, 1, ncolors))]
 
 
+def colorcet_cmap_to_palette(cmap, ncolors=None, categorical=False):
+    from colorcet import palette
+
+    categories = ['glasbey']
+
+    ncolors = ncolors or 256
+    cmap_categorical = any(c in cmap for c in categories)
+
+    if cmap.endswith('_r'):
+        palette = list(reversed(palette[cmap[:-2]]))
+    else:
+        palette = palette[cmap]
+
+    return resample_palette(palette, ncolors, categorical, cmap_categorical)
+
+
 def bokeh_palette_to_palette(cmap, ncolors=None, categorical=False):
     from bokeh import palettes
 
@@ -589,14 +619,7 @@ def bokeh_palette_to_palette(cmap, ncolors=None, categorical=False):
         palette = palette(ncolors)
     if reverse: palette = palette[::-1]
 
-    if len(palette) != ncolors:
-        if categorical and cmap_categorical:
-            palette = [palette[i%len(palette)] for i in range(ncolors)]
-        else:
-            lpad, rpad = -0.5, 0.49999999999
-            indexes = np.linspace(lpad, (len(palette)-1)+rpad, ncolors)
-            palette = [palette[int(np.round(v))] for v in indexes]
-    return palette
+    return resample_palette(palette, ncolors, categorical, cmap_categorical)
 
 
 def linear_gradient(start_hex, finish_hex, n=10):
@@ -865,16 +888,12 @@ def process_cmap(cmap, ncolors=None, provider=None, categorical=False):
         mpl_cmaps = _list_cmaps('matplotlib')
         bk_cmaps = _list_cmaps('bokeh')
         cet_cmaps = _list_cmaps('colorcet')
-        if provider=='matplotlib' or (provider is None and (cmap in mpl_cmaps or cmap.lower() in mpl_cmaps)):
+        if provider == 'matplotlib' or (provider is None and (cmap in mpl_cmaps or cmap.lower() in mpl_cmaps)):
             palette = mplcmap_to_palette(cmap, ncolors, categorical)
-        elif provider=='bokeh' or (provider is None and (cmap in bk_cmaps or cmap.capitalize() in bk_cmaps)):
+        elif provider == 'bokeh' or (provider is None and (cmap in bk_cmaps or cmap.capitalize() in bk_cmaps)):
             palette = bokeh_palette_to_palette(cmap, ncolors, categorical)
-        elif provider=='colorcet' or (provider is None and cmap in cet_cmaps):
-            from colorcet import palette
-            if cmap.endswith('_r'):
-                palette = list(reversed(palette[cmap[:-2]]))
-            else:
-                palette = palette[cmap]
+        elif provider == 'colorcet' or (provider is None and cmap in cet_cmaps):
+            palette = colorcet_cmap_to_palette(cmap, ncolors, categorical)
         else:
             raise ValueError("Supplied cmap %s not found among %s colormaps." %
                              (cmap,providers_checked))
diff --git a/holoviews/streams.py b/holoviews/streams.py
index 24d8a64c14..39b2996916 100644
--- a/holoviews/streams.py
+++ b/holoviews/streams.py
@@ -338,10 +338,12 @@ def source(self):
 
     @source.setter
     def source(self, source):
-        if self.source:
+        if self.source is not None:
             source_list = self.registry[self.source]
             if self in source_list:
                 source_list.remove(self)
+            if not source_list:
+                self.registry.pop(self.source)
 
         if source is None:
             self._source = None
diff --git a/holoviews/tests/teststreams.py b/holoviews/tests/teststreams.py
index 3107f985ae..113af287a7 100644
--- a/holoviews/tests/teststreams.py
+++ b/holoviews/tests/teststreams.py
@@ -627,6 +627,15 @@ def test_source_empty_element(self):
         stream = PointerX(source=points)
         self.assertIs(stream.source, points)
 
+    def test_source_empty_element_remap(self):
+        points = Points([])
+        stream = PointerX(source=points)
+        self.assertIs(stream.source, points)
+        curve = Curve([])
+        stream.source = curve
+        self.assertNotIn(points, Stream.registry)
+        self.assertIn(curve, Stream.registry)
+
     def test_source_empty_dmap(self):
         points_dmap = DynamicMap(lambda x: Points([]), kdims=['X'])
         stream = PointerX(source=points_dmap)
diff --git a/holoviews/util/__init__.py b/holoviews/util/__init__.py
index 98e9a53c4b..d4f5eac895 100644
--- a/holoviews/util/__init__.py
+++ b/holoviews/util/__init__.py
@@ -921,6 +921,11 @@ def _eval_kwargs(self):
         for k, v in self.p.kwargs.items():
             if util.is_param_method(v):
                 v = v()
+            elif isinstance(v, FunctionType) and hasattr(v, '_dinfo'):
+                deps = v._dinfo
+                args = (getattr(p.owner, p.name) for p in deps.get('dependencies', []))
+                kwargs = {k: getattr(p.owner, p.name) for k, p in deps.get('kw', {}).items()}
+                v = v(*args, **kwargs)
             evaled_kwargs[k] = v
         return evaled_kwargs