[Symphony] modelling language for symphony

[Ashutosh Mahajan]

On Mon, 21 Sep 2009, G Chandramouli wrote:

>    Hi,
>        I am doing my thesis in MIP of location problem. I am using LINGO but
>    it is very slow. I have 400 binary variables and over 200000 constraints.

are you giving LINGO all the constraints at once? have you tried starting with
few constraints and adding only those that are violated later? 

>    I want to use symphony but I don't have a proper modelling language. AMPL
>    is costly and can't be afforded. Can I model it on AMPL limited (free)
>    version using symphony solver.

i dont think the free version allows you to model a problem with such a size.

> Can GMPL be used for modelling such a large problem? What about FLOPC++ ? 

either should work, but i havent used them myself.

> Any limitations with these languages for
>    large problems? Also suggest me an alternative , in case above languages
>    fail
>    Pls. tell me whether symphony is faster than LINGO and Cplex in case of
>    parallel systems and individual system.

we havent compared symphony to LINGO, but we are definitely slower than Cplex.
also, if you have cplex, you will most probably have access to ampl or
gams for modelling as well.

--
regards
Ashutosh Mahajan
http://coral.ie.lehigh.edu/~asm4