[gradsusr] lats4d and used defined variable

[Becker, Bernd]

Dear all, 
I grapple with lats4d and writing a user defined variable
in grib_format. 

How can I achieve the following:

open file.ctl  (contains tmax amongst other things)
define pop=tmax/2.

lats4d -v -q -i  file.ctl -vars pop  -o ex2a -format grads_grib

the follwing works just fine:

lats4d -v -q -i  ex2a.ctl -vars tmax  -o ex2a -format grads_grib

This runs in a 1.9 built.

In the real case, pop is a lot more complicated than tmax/2.

Thanks for your suggestions!
Have a nice weekend.
Bernd.

--
Bernd Becker   Climate Impacts Product Development
Met Office Hadley Centre    FitzRoy Road  Exeter   Devon EX1 3PB  United
Kingdom
Tel.: +44 (0) 1392 884511 Fax: +44 (0)870 900 5050
E-mail:bernd.becker at metoffice.gov.uk -
http://www.metoffice.gov.uk/research/our-scientists/seasonal-to-decadal/
bernd-becker