faster grid generation

interp/grid/__init__.py

@@ -89,10 +89,9 @@ class grid(object):
       grid object (collection of verts and q).
 
       note: the input is indicies, the grid contains verts
-    """
-    p = [self.verts[i]  for i in indicies]
-    q = [self.q[i]      for i in indicies]
-    return grid(p, q)
+   """
+
+    return grid(self.verts[indicies], self.q[indicies])
 
   def get_simplex_and_nearest_points(self, X, extra_points = 3):
     """