Unlimit the vdim bounds and add ability for additional vdim hover (#3193

)

holoviews/element/raster.py

@@ -246,7 +246,7 @@ class Image(Dataset, Raster, SheetCoordinateSystem):
         of a string or dimension object.""")
 
     vdims = param.List(default=[Dimension('z')],
-                       bounds=(1, 1), doc="""
+                       bounds=(1, None), doc="""
         The dimension description of the data held in the matrix.""")
 
     rtol = param.Number(default=None, doc="""

holoviews/plotting/bokeh/raster.py

@@ -27,8 +27,11 @@ def _hover_opts(self, element):
         xdim, ydim = element.kdims
         tooltips = [(xdim.pprint_label, '$x'), (ydim.pprint_label, '$y')]
         if bokeh_version >= '0.12.16' and not isinstance(element, (RGB, HSV)):
-            vdim = element.vdims[0]
-            tooltips.append((vdim.pprint_label, '@image'))
+            vdims = element.vdims
+            tooltips.append((vdims[0].pprint_label, '@image'))
+            for vdim in vdims[1:]:
+                vname = dimension_sanitizer(vdim.name)
+                tooltips.append((vdim.pprint_label, '@{0}'.format(vname)))
         return tooltips, {}
 
     def __init__(self, *args, **kwargs):
@@ -38,40 +41,46 @@ def __init__(self, *args, **kwargs):
 
     def get_data(self, element, ranges, style):
         mapping = dict(image='image', x='x', y='y', dw='dw', dh='dh')
-        val_dim = [d for d in element.vdims][0]
+        val_dim = element.vdims[0]
         style['color_mapper'] = self._get_colormapper(val_dim, element, ranges, style)
 
         if self.static_source:
             return {}, mapping, style
 
-        img = element.dimension_values(2, flat=False)
-        if img.dtype.kind == 'b':
-            img = img.astype(np.int8)
-
         if type(element) is Raster:
             l, b, r, t = element.extents
             if self.invert_axes:
                 l, b, r, t = b, l, t, r
-            else:
-                img = img.T
         else:
             l, b, r, t = element.bounds.lbrt()
             if self.invert_axes:
-                img = img.T
                 l, b, r, t = b, l, t, r
 
         if self.invert_xaxis:
             l, r = r, l
-            img = img[:, ::-1]
         if self.invert_yaxis:
-            img = img[::-1]
             b, t = t, b
         dh, dw = t-b, r-l
+        data = dict(x=[l], y=[b], dw=[dw], dh=[dh])
+
+        for i, vdim in enumerate(element.vdims, 2):
+            if i > 2 and 'hover' not in self.handles:
+                continue
+            img = element.dimension_values(i, flat=False)
+            if img.dtype.kind == 'b':
+                img = img.astype(np.int8)
+            if 0 in img.shape:
+                img = np.array([[np.NaN]])
+            if ((self.invert_axes and not type(element) is Raster) or
+                (not self.invert_axes and type(element) is Raster)):
+                img = img.T
+            if self.invert_xaxis:
+                img = img[:, ::-1]
+            if self.invert_yaxis:
+                img = img[::-1]
+            key = 'image' if i == 2 else dimension_sanitizer(vdim.name)
+            data[key] = [img]
 
-        if 0 in img.shape:
-            img = np.array([[np.NaN]])
-
-        data = dict(image=[img], x=[l], y=[b], dw=[dw], dh=[dh])
         return (data, mapping, style)