dset ndvi1km.gdat
*indset /clima/oper/nmme5ANA/grads/input_g 
undef -3000
title avn model 
*options yrev
xdef  8368 linear  10.64178  0.008023657
ydef 3739 linear  19.99955   0.008023657
tdef 1 linear 00Z017jan2018 01hr 
zdef 1 levels 1 
vars 1 
ndvi  0  12,40,4       ! dust mask 
endvars