Require 2-dimensional array in insert_function

src/filter.py

@@ -309,6 +309,7 @@ class Filter(object):
         'args': opaque arguments passed to process_numpy
 
         'insert_func': function to call in order to insert array of data.
+        Should be passed a 2-dimensional array of data to insert.
         Data timestamps must be within the provided interval.
 
         'final': True if this is the last bit of data for this
@@ -337,6 +338,8 @@ class Filter(object):
                           interval.start, interval.end) as insert_ctx:
                 def insert_function(array):
                     s = cStringIO.StringIO()
+                    if len(np.shape(array)) != 2:
+                        raise Exception("array must be 2-dimensional")
                     np.savetxt(s, array)
                     insert_ctx.insert(s.getvalue())