gams file to matlab

Hi, all

My gams file can not run more than 48 datas and then the professor
suggested me change to matlab, which he thought could handle much more
data sets.

Is there anyone to know how to exchange gams file to matlab file, any
suggestion and any link would be highly appreciated.

Best regards
Jens

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it is not clear what you are talking about. GAMS is a
modeling language, Matlab is not. You may not use GAMS
properly or have a limited license. The very first thing
one has to know is which types of problems you are
trying to solve.


On May 24, 1:26 pm, Jens wrote:

Hi, all

My gams file can not run more than 48 datas and then the professor
suggested me change to matlab, which he thought could handle much more
data sets.

Is there anyone to know how to exchange gams file to matlab file, any
suggestion and any link would be highly appreciated.

Best regards
Jens
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Hi, all

Sorry I can not make myself understood.

I programed an optimization problem in gams, and it took 6 hours to
handle 48 data. And after checking, my tutor said I could try to
program the same optimization problem in matlab, which he thought can
run faster and more data. Because I am not skilled at Matlab, so I
would like to have a shortcut that if I can exchange .gms file to .m
file, like word file coverting to PDF file ect.

Any suggestion?

Best regards
Jens


On May 24, 10:49 pm, “mittelm…@asu.edu” wrote:

it is not clear what you are talking about. GAMS is a
modeling language, Matlab is not. You may not use GAMS
properly or have a limited license. The very first thing
one has to know is which types of problems you are
trying to solve.

On May 24, 1:26 pm, Jens wrote:

Hi, all

My gams file can not run more than 48 datas and then the professor
suggested me change to matlab, which he thought could handle much more
data sets.

Is there anyone to know how to exchange gams file to matlab file, any
suggestion and any link would be highly appreciated.

Best regards
Jens- Hide quoted text -

Another option is to try with a different solver (like glpk)- maybe that’ll work?


Cheers
Kretch

On Sun, May 24, 2009 at 11:18 PM, Jens wrote:


Hi, all

Sorry I can not make myself understood.

I programed an optimization problem in gams, and it took 6 hours to
handle 48 data. And after checking, my tutor said I could try to
program the same optimization problem in matlab, which he thought can
run faster and more data. Because I am not skilled at Matlab, so I
would like to have a shortcut that if I can exchange .gms file to .m
file, like word file coverting to PDF file ect.

Any suggestion?

Best regards
Jens


On May 24, 10:49 pm, “mittelm…@asu.edu” wrote:

it is not clear what you are talking about. GAMS is a
modeling language, Matlab is not. You may not use GAMS
properly or have a limited license. The very first thing
one has to know is which types of problems you are
trying to solve.

On May 24, 1:26 pm, Jens wrote:

Hi, all

My gams file can not run more than 48 datas and then the professor
suggested me change to matlab, which he thought could handle much more
data sets.

Is there anyone to know how to exchange gams file to matlab file, any
suggestion and any link would be highly appreciated.

Best regards
Jens- Hide quoted text -

Hi all

Thank you very much for help and nice to meet kind people here.

I will try all the alternitive versions and any progress, will post
up.

Best regards
Jens



On May 25, 8:28 am, Yaron Kretchmer wrote:

Another option is to try with a different solver (like glpk)- maybe that’ll
work?

Cheers
Kretch

On Sun, May 24, 2009 at 11:18 PM, Jens wrote:

Hi, all

Sorry I can not make myself understood.

I programed an optimization problem in gams, and it took 6 hours to
handle 48 data. And after checking, my tutor said I could try to
program the same optimization problem in matlab, which he thought can
run faster and more data. Because I am not skilled at Matlab, so I
would like to have a shortcut that if I can exchange .gms file to .m
file, like word file coverting to PDF file ect.

Any suggestion?

Best regards
Jens

On May 24, 10:49 pm, “mittelm…@asu.edu” wrote:

it is not clear what you are talking about. GAMS is a
modeling language, Matlab is not. You may not use GAMS
properly or have a limited license. The very first thing
one has to know is which types of problems you are
trying to solve.

On May 24, 1:26 pm, Jens wrote:

Hi, all

My gams file can not run more than 48 datas and then the professor
suggested me change to matlab, which he thought could handle much more
data sets.

Is there anyone to know how to exchange gams file to matlab file, any
suggestion and any link would be highly appreciated.

Best regards
Jens- Hide quoted text -

  • Show quoted text – Hide quoted text -

Jens,
it would be really good if you told us which kinf of problem
you are solving. GAMS itself is not solving your problem it
is only converting it to the input of a solver. The question
is now how long does in your case the conversion/processing
by GAMS take and how long does the solver take.
There are cases where the first can be reduced but more likely
it is the second phase that is taking up most of the time.
Matlab basically does the same, but they have partly different
solvers.
HM

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Sometime in May, Jens proposed the following:

|
| Hi, all
|
| Sorry I can not make myself understood.
|
| I programed an optimization problem in gams, and it took 6 hours to
| handle 48 data. And after checking, my tutor said I could try to
| program the same optimization problem in matlab, which he thought can
| run faster and more data. Because I am not skilled at Matlab, so I
| would like to have a shortcut that if I can exchange .gms file to .m
| file, like word file coverting to PDF file ect.
|
| Any suggestion?


Jens,

What kind of a model are you trying to implement in matlab? If you have
integer variables in your model and you intend to do some sort of
optimization, I don’t believe that the optimization toolbox in matlab will
do this. It didn’t a couple years ago at least, so it’s possible that it
can solve IP and MIP types of problems now. To the best of my knowledge the
only way to do this in matlab is to purchase something like Tomslab —
this is a matlab interface to different solvers (e.g., CPLEX).

Problem formulation can impact solution speed. If you could describe the
problem you are trying to solve, some of the people here may be able to
help. It’s not terribly clear to me what you mean by 48 data. Is that the
number of variables?

There may be a posting FAQ somewhere, but I think some of the important
things to mention would include:

What kind of problem are you trying to solve (MIP, IP, MINLP, NLP, etc.).

If the system is nonlinear what is the nature of the nonlinearities? Is
it bilinear (a product of two variable), exponential, etc.

How many equations and variables are created at execution?

Does gams give you any interesting output that might indicate problems
(like numerical issues).

\

Just one correction to John’s post. It is not necessary to buy
TOMLAB, There are free Matlab interfaces to various solvers. The
solver needs to be bought if commercial, but there also are
quite a few free ones for various problems.
http://plato.asu.edu/guide.html

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