Conversion from Sigma coor. to standard pressure levels

[Li Dong]

Dear GrADS users,

Currently I am dealing with datasets, downloaded from NCEP reanalyses, in
two different coordinates. One is sigma vertical coor. on Gaussian grids,
and the other is on standard pressure levels, with lon-lat grids. Is there
any conversion routine that can do this job? If anyone happens to have
one, may I share it with you? Many thanks.

Best regards,

Li