php as a constraints solver

[choubix]

hello,

just wondering whether people around here use php as a constraint solver like excel's solver.

I'm asked to maximize and minimize a set of variables according to multiple constraints.

I was wondering if there were libraries dealing with that...

thanks!

[wilku]

I think you'd be better off with c++ or even fortran (if anybody uses it these days). There are plenty of libraries for that (lpsolve for one). If you need to use some results online, you can write the solver in c++ and then run it as system command in php. Alternatively you can add your own function and a library to php and compile it from source (never done this before though, but I think it would be harder).

EDIT: With lpsolve you won't even have to compile your own solver - it has already been made. Just prepare data in some given format in a file and the solver would give you the results - so you can use php to prepare the data, run the solver and present results to user.

[choubix]

hello wilku, thanks for your answer.

i remember having a quick look at IPsolve.
It's an inattrative piece of software that seemed extremely powerful.
apparently there is an active group behind (people feeling the limitations of Excel's solver...).

do you think it is possible to run the solver "online"?

the idea behind would be to run a cron job:
- retrieve the data set in a foramt readable by the solver,
- send data to the sovler (where constraints will ahve been defined)
- send the result back to the database

i am a bit confused with this. really dont know how to attack the problem...

A.

[choubix]

ok, the doc says you can access the API from any application.
seems promising. I'll need to find good tutorials though. remember it was not that straightforward 😉

thanks wilku