[GAMSlinks] IPOPT options through GAMS

[Stefan Vigerske]

Hi,

> I am trying to run a nonlinear problem with IPOPT through GAMS.
> I made a ipopt.opt file where I write my ipopt options. I tried to save this file in several locations, but it is never recognize by GAMS.
> 
> Does anybody know where the right location for the file is? and whether this is the right file name and extension for defining the options?

The right place is the directory from which you start GAMS.
To make GAMS/Ipopt recognize this file, you need to either give the 
option optfile=1 at the gams command line (gams <model> optfile=1) or 
put a <modelname>.optfile=1 statement in your gams model file.
Otherwise, GAMS/Ipopt does not read an option file.

Btw, you can use alternative option files ipopt.op2, ipopt.op3, ..., 
ipopt.o12, ... by setting optfile=2, optfile=3, ..., optfile=12, ...

Best,
Stefan

-- 
Stefan Vigerske
Humboldt University Berlin, Numerical Mathematics
http://www.math.hu-berlin.de/~stefan