diff --git a/system/plots.py b/system/plots.py
index 61bb72f..3c4d6c0 100644
--- a/system/plots.py
+++ b/system/plots.py
@@ -460,7 +460,6 @@ class ScatterPlot(Plot):
         return self._toolbar
 
     def rectangle_select_callback(self, x1, y1, x2, y2):
-        'event1 and event2 are the press and release events'
         ydata = self.yaxis_data
         xdata = self.xaxis_data
 
@@ -479,20 +478,13 @@ class ScatterPlot(Plot):
                 #logger.log('debug','Selection y_start bigger than y_end')
                 index =scipy.nonzero((xdata>x1) & (xdata<x2) & (ydata<y1) & (ydata>y2))
 
-        # generate ids for selected indices
-        reverse = {}
-        for key, value in self.dataset[self.current_dim].items():
-            reverse[value] = key
-        ids = []
-        for ind in index:
-            ids.append(reverse[ind])
-            
-        self.selection_listener(self.current_dim,ids)
+        ids = self.dataset.get_identifiers(self.current_dim, index)
+        self.selection_listener(self.current_dim, ids)
 
     def selection_changed(self, selection):
         ids = selection[self.current_dim] # current identifiers
         
-        index = [ind for id,ind in self.dataset[self.current_dim].items() if id in ids] #conversion to index
+        index = self.dataset.get_indices(self.current_dim, ids)
         xdata_new = scipy.take(self.xaxis_data,index) #take data
         ydata_new = scipy.take(self.yaxis_data,index)
         self.ax.clear()