Added handling for isocontour kdims on MultiInterface

holoviews/core/data/multipath.py

@@ -45,7 +45,17 @@ def init(cls, eltype, data, kdims, vdims):
 
     @classmethod
     def validate(cls, dataset):
-        pass
+        # Ensure that auxilliary key dimensions on each subpaths are scalar
+        if dataset.ndims <= 2:
+            return
+        ds = cls._inner_dataset_template(dataset)
+        for d in dataset.data:
+            ds.data = d
+            for dim in dataset.kdims[2:]:
+                if len(ds.dimension_values(dim, expanded=False)) > 1:
+                    raise ValueError("'%s' key dimension value must have a constant value on each subpath, "
+                                     "for paths with value for each coordinate of the array declare a "
+                                     "value dimension instead." % dim)
 
     @classmethod
     def _inner_dataset_template(cls, dataset):
@@ -163,18 +173,29 @@ def redim(cls, dataset, dimensions):
     def values(cls, dataset, dimension, expanded, flat):
         """
         Returns a single concatenated array of all subpaths separated
-        by NaN values. If not expanded NaN separators are not included.
+        by NaN values. If expanded keyword is False an array of arrays
+        is returned.
         """
         if not dataset.data:
             return np.array([])
         values = []
         ds = cls._inner_dataset_template(dataset)
+        didx = dataset.get_dimension_index(dimension)
         for d in dataset.data:
             ds.data = d
-            values.append(ds.interface.values(ds, dimension, expanded, flat))
+            expand = expanded if didx>1 and dimension in dataset.kdims else True
+            dvals = ds.interface.values(ds, dimension, expand, flat)
+            values.append(dvals)
             if expanded:
                 values.append([np.NaN])
-        return np.concatenate(values[:-1] if expanded else values) if values else []
+            elif not expand and len(dvals):
+                values[-1] = dvals[0]
+        if not values:
+            return np.array()
+        elif expanded:
+            return np.concatenate(values[:-1])
+        else:
+            return np.array(values)
 
     @classmethod
     def split(cls, dataset, start, end):

holoviews/element/path.py

@@ -31,7 +31,7 @@ class Path(Dataset, Element2D):
     """
 
     kdims = param.List(default=[Dimension('x'), Dimension('y')],
-                       constant=True, bounds=(2, 2), doc="""
+                       constant=True, bounds=(2, None), doc="""
         The label of the x- and y-dimension of the Image in form
         of a string or dimension object.""")
 

tests/testmultiinterface.py

@@ -69,12 +69,22 @@ def test_multi_array_shape(self):
         arrays = [np.column_stack([np.arange(i, i+2), np.arange(i, i+2)]) for i in range(2)]
         mds = Path(arrays, kdims=['x', 'y'], datatype=['multitabular'])
         self.assertEqual(mds.shape, (5, 2))
-    
+
     def test_multi_array_values(self):
         arrays = [np.column_stack([np.arange(i, i+2), np.arange(i, i+2)]) for i in range(2)]
         mds = Path(arrays, kdims=['x', 'y'], datatype=['multitabular'])
         self.assertEqual(mds.dimension_values(0), np.array([0., 1, np.NaN, 1, 2]))
 
+    def test_multi_array_values_coordinates_nonexpanded(self):
+        arrays = [np.column_stack([np.arange(i, i+2), np.arange(i, i+2)]) for i in range(2)]
+        mds = Path(arrays, kdims=['x', 'y'], datatype=['multitabular'])
+        self.assertEqual(mds.dimension_values(0, expanded=False), np.array([[0., 1], [1, 2]]))
+
+    def test_multi_array_values_coordinates_nonexpanded_constant_kdim(self):
+        arrays = [np.column_stack([np.arange(i, i+2), np.arange(i, i+2), np.ones(2)*i]) for i in range(2)]
+        mds = Path(arrays, kdims=['x', 'y', 'z'], datatype=['multitabular'])
+        self.assertEqual(mds.dimension_values(2, expanded=False), np.array([0, 1]))
+
     def test_multi_array_redim(self):
         arrays = [np.column_stack([np.arange(i, i+2), np.arange(i, i+2)]) for i in range(2)]
         mds = Path(arrays, kdims=['x', 'y'], datatype=['multitabular']).redim(x='x2')
@@ -87,10 +97,19 @@ def test_multi_mixed_interface_raises(self):
         error = "None of the available storage backends were able to support the supplied data format."
         with self.assertRaisesRegexp(ValueError, error):
             mds = Path(arrays, kdims=['x', 'y'], datatype=['multitabular'])
-    
+
     def test_multi_mixed_dims_raises(self):
         arrays = [{'x': range(10), 'y' if j else 'z': range(10)}
                   for i in range(2) for j in range(2)]
         error = "None of the available storage backends were able to support the supplied data format."
         with self.assertRaisesRegexp(ValueError, error):
             mds = Path(arrays, kdims=['x', 'y'], datatype=['multitabular'])
+
+    def test_multi_nonconstant_kdims_raises(self):
+        arrays = [{'x': range(10), 'y': range(10), 'z': range(10)}
+                  for i in range(2)]
+        error = ("z' key dimension value must have a constant value on each subpath, "
+                 "for paths with value for each coordinate of the array declare a "
+                 "value dimension instead.")
+        with self.assertRaisesRegexp(ValueError, error):
+            mds = Path(arrays, kdims=['x', 'y', 'z'], datatype=['multitabular'])