diff --git a/lib/grid/__init__.py b/lib/grid/__init__.py
index 91d26d0..ebbb249 100644
--- a/lib/grid/__init__.py
+++ b/lib/grid/__init__.py
@@ -32,7 +32,7 @@ class grid(object):
 
   def __init__(self, points, q):
     """
-      this thing eats two pre-constructed arrays of stuff:
+      this thing eats two pre-constructed arrays of floats:
       points = array of arrays (i will convert to numpy.array)
                [[x0,y0], [x1,y1], ...]
       q      = array (1D) of important values