removed redundant grid class definition

interp/grid/DD.py

@@ -5,11 +5,8 @@ from interp.tools import exact_func, log
 import numpy as np
 
 
-class grid(basegrid):
-  def __init__(self, verts, q):
-    basegrid.__init__(self, verts, q)
 
-class rect_grid(grid):
+class rect_grid(basegrid):
   def __init__(self, xres = 5, yres = 5):
     xmin = -1.0
     xmax =  1.0