* system/plots.py: Added NetworkPlot, which may or may not work correctly.

* system/dataset.py: Removed a few lines of obsolete code.

system/dataset.py

@@ -113,10 +113,7 @@ class Dataset:
         
     def asarray(self):
         """Returns the numeric array (data) of dataset"""
-        if not self.has_array:
-            raise ValueError, "Dataset is empty"
-        else:
-            return self._array
+        return self._array
 
     def add_array(self,array):
         """Adds array as an ArrayType object.
@@ -199,14 +196,7 @@ class CategoryDataset(Dataset):
     
     def __init__(self):
         Dataset.__init__(self)
-        self.has_collection = False
             
-    def as_array(self):
-        """Returns data as binary matrix"""
-        if not self.has_array and self.has_collection:
-            #build numeric array
-            pass
-
     def as_collection(self,dim):
         """Returns data as collection along dim"""
         pass
@@ -236,7 +226,7 @@ class GraphDataset(Dataset):
         self.has_graph = False
         
     def asnetworkx(self,nx_type='graph'):
-        dim = self.get_dim_names()[0]
+        dim = self.get_dim_name()[0]
         ids = self.get_identifiers(dim)
         adj_mat = self.asarray()
         G = self._graph_from_adj_matrix(adj_mat,labels=ids)
@@ -270,6 +260,7 @@ class GraphDataset(Dataset):
                     tail = labels[i]
                     G.add_edge(head,tail)
         return G
+
 Dataset._all_dims=set()
 
 class Selection: