eloop(expr)
The eloop function is similar to the tloop function. When displaying a GrADS expression (expr) with the E (Ensemble) dimension varying, the
eloop function will evaluate the expr with each designated ensemble member fixed, then reassemble the grids to obtain a final result
that is E-varying.
The eloop function is provided as a way to obtain E-varying results
from functions or expressions that are unable to operate
when E is a varying dimension.
open fcst.ctl
open rean.ctl
set lon -77
set lat 39
set e 1 15
set t 1 last
d eloop(t2m.1-t2m.2(e=1))