diff -r a5ff3ac7cb43 -r e8327b4e8b8b server/python/django/renkanmanager/utils.py
--- a/server/python/django/renkanmanager/utils.py	Mon Jan 05 14:02:12 2015 +0100
+++ b/server/python/django/renkanmanager/utils.py	Mon Jan 05 17:29:55 2015 +0100
@@ -42,7 +42,7 @@
 
 
 
-class LineNodePlacer(NodePlacer):
+class LineNodePlacer(NodePlacer): #vertical lines
     
     max_length = 0
     
@@ -66,6 +66,29 @@
                     self.cat_nb_nodes[c].append({ "x": order*500, "y": 100*(i+offset) })
 
 
+class HorLineNodePlacer(NodePlacer): #horizontal lines
+    
+    max_length = 0
+    
+    def init(self, cat_nb_nodes_initial):
+        for c in cat_nb_nodes_initial:
+            nb = cat_nb_nodes_initial[c]
+            if isinstance(cat_nb_nodes_initial[c], tuple):
+                _, nb = nb
+            self.max_length = nb if nb > self.max_length else self.max_length
+        for i_cat,c in enumerate(cat_nb_nodes_initial):
+            self.cat_nb_nodes[c] = []
+            order = i_cat
+            nb = cat_nb_nodes_initial[c]
+            if isinstance(cat_nb_nodes_initial[c], tuple):
+                order, nb = nb
+            offset = float(self.max_length - nb) / 2
+            for i in xrange(nb):
+                if c=="northwest":
+                    self.cat_nb_nodes[c].append({ "x": offset, "y": order*500 })
+                else:
+                    self.cat_nb_nodes[c].append({ "x": 100*(i+offset), "y": order*500 })
+
 
 class CircleNodePlacer(NodePlacer):