Graphs, iostat, nan

I have an iostat2 test that runs and graphs wait & busy

times of nfs mounts and disk mounts.

 
However, I have a lot of nan's in the data due to the

nfs mount or disk mount has no wait or busy times.

 
Is there a way when you display the graph to tell it not

to show any data with nan? It lists every partition with

the "NaN" values. I only want to see the data that has

values.

 
James