Assuming the previous cycle's forecast is in a different grid file - you
will need to have the program open two files.
gdfile= currentcycle.grd + previouscycle.grd
Now you can reference these grids in the gdpfun parameter...
(where a +2 indicated get hght from the second file defined in gdfile)
Also - in any program (example - gdinfo), type "ph" at the command prompt
followed by a parameter name to get more info on how to use the parameter.
For example "ph gdfile" will spell out for you how to reference different
grid files in the "gdfile" parameter and "ph gfunc" will spell out how to
reference different fields from the different files.
gembud-bounces@xxxxxxxxxxxxxxxx wrote on 09/10/2007 05:16:53 PM:
I'm trying to write a script that makes a comparison of
the most current
model run, say 24h forecast, versus the previous cycle's
(say it is 6h
earlier) 30h forecast, effectively valid at the same time.
I'd like to
just be able to see changes in the model solution from
previous runs. I
have something like:
gdpfun= sub(hght^1200f012, hght^0600f018)
which actually works, but I'd like to be able to do
something like this
with specifying the times, but a more general script in which it
compares the last run versus the previous one, something
in the form of:
gdpfun= sub(hght^last, hght^'(last-1)')
I'd appreciate any suggestions as soon as possible.