```python import vcs import cdms2 f=cdms2.open(vcs.sample_data+"/clt.nc") s=f("clt") x=vcs.init() x.plot(s) s2=cdms2.MV2.masked_greater(s,50.) gm =x.createboxfill() gm.missing=[50,50,50,50] x.plot(s2,gm) raw_input("press enteR") ``` gives: 
gives:
