Matrix inverse

GAMS
1

Hello everyone,
I’m now starting to program in GAMS.
I would to know if there is a function to invert a matrix.

Thank you,
bye,
Francesco

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2

Hi Francesco
See the gdx-tools documentation (p36, “invert”)
Renger

On Wed, Jun 13, 2012 at 3:24 PM, aser wrote:

Hello everyone,
I’m now starting to program in GAMS.
I would to know if there is a function to invert a matrix.

Thank you,
bye,
Francesco

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Renger van Nieuwkoop

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3

On 13/06/2012 11:24 PM, aser wrote:

Hello everyone,
I’m now starting to program in GAMS.
I would to know if there is a function to invert a matrix.

Thank you,
bye,
Francesco

you could try the file ‘gauss.xxx’ in the gams modlib directory … (apologies if it’s moved or changed, my version of gams is a bit old)

rob


Robert Waschik
Senior Lecturer
School of Economics/Faculty of Business, Economics and Law
La Trobe University | Bundoora 3086
T: 03 9479 5701 | F: 03 9479 1654
E: r.waschik@latrobe.edu.au
www.latrobe.edu.au

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4

I would to know if there is a function to invert a matrix.
there’s no such a function in GAMS.

As far as I know, there are 3 ways to invert a matrix in GAMS,

  1. unload to gdx gile and use invert.exe in gams sysdir
  2. unload to gdx file and call lapack routines
  3. use another variable, and solve lp problem under constrain X * Xv = I


    HTH,

Yan

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5

Hello,

Checking out the “gauss” example model from the GAMS model library is a good idea, but we recommend you do not poke around in the modlib directory. Intended usage is to use the gamslib command to extract the model (and any required supporting files) to the current directory, or do this via the IDE with the “Model Libraries” menu (next to the Help menu). For example on the command line:

% mkdir myStuff
% cd myStuff
% gamslib gauss
% gams gauss

Examples and tests for the invert utility can be gotten from our Test Library, via the IDE or like this:

% mkdir myStuff
% cd myStuff
% testlib invert01
% gams invert01
% testlib invert02
% gams invert02

-Steve

On Wed, Jun 13, 2012 at 7:19 PM, Robert Waschik wrote:

On 13/06/2012 11:24 PM, aser wrote:

Hello everyone,
I’m now starting to program in GAMS.
I would to know if there is a function to invert a matrix.

Thank you,
bye,
Francesco


you could try the file ‘gauss.xxx’ in the gams modlib directory … (apologies if it’s moved or changed, my version of gams is a bit old)

rob


Robert Waschik
Senior Lecturer
School of Economics/Faculty of Business, Economics and Law
La Trobe University | Bundoora 3086
T: 03 9479 5701 | F: 03 9479 1654
E: r.waschik@latrobe.edu.au
www.latrobe.edu.au

CRICOS Provider 00115M

Please kindly consider your environment before printing this e-mail

Warning to recipients:
This email and any attachments are confidential and subject to
copyright. If you are not the intended recipient any use, disclosure
or copying is unauthorised. If you have received this email in error
please advise us immediately by reply email and delete all copies. It
is your responsibility to examine this email and any attachments for
viruses. Any personal information in this email must be handled in
accordance with the Information Privacy Act 2000 (Vic).


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Steven Dirkse, Ph.D.
GAMS Development Corp., Washington DC
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sdirkse@gams.com
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