extracting from pyGrADs

[Shun Jie Liu]

Hi GrADs users,
 
I am using pyGrADs and went through the examples adn tutorial and everything seems ok.
 
 
I can display variable T2 using my own data file on iPython using 
 
d T2
 
However, when I try to extract from the data file using
 
xx T2 
 
I got an error,
 
<class 'grads.gacore.GrADSError'>: 'invalid exchange metadata (idim,jdim)=(0,-2147483648) - make sure <T2> is valid and that lon/lat is varying