* annotations.py: Annotation class for two-way annotations. Does only support

exactly two dimensions.

system/annotations.py

@@ -0,0 +1,33 @@
+import logger
+
+class Annotations:
+    def __init__(self, *dimensions):
+        """ Initializes a new Annotation with the given dimension labels.
+        dimensions is a list of dimension labels.
+        """ 
+        if len(dimensions) == 2:
+            logger.log('error', 'Annotations only supports two dimensions.')
+
+        self.dimensions = {}
+        for d in dimensions:
+            self.dimensions[d] = {}
+
+    def add_annotations(self, dim, id, ann_dim, annotations):
+        if not self.dimensions[dim]:
+            logger.log('warning', 'Annotations object does not contain dimension %s' % dim)
+            return None
+        for a in annotations:
+            self.annotations[ann_dim][a].add(id)
+        self.annotations[dim][id] = annotations
+        
+    def get_annotations(self, dim, id):
+        if not self.dimensions[dim]:
+            logger.log('warning', 'Annotations object does not contain dimension %s' % dim)
+            return None
+
+        if self.dimensions[dim].has_key(id):
+            return self.dimensions[dim][id].values()
+        return None
+
+    def has_dimension(self, dim):
+        return self.dimensions.has_key(dim)