Dear GAMS users,
have you ever coded an algorithm to find cycles in an undirected graph with GAMS? If so, could you share it? Otherwise, any help is most welcome 
Best regards
Fede
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Fede: Hi, I would find that useful. So I offer my help to develop/test. Feel free to write me if you want to work together.
Regards
Claudio
On Thu, Feb 26, 2015 at 2:45 PM, Federico Perea wrote:
Dear GAMS users,
have you ever coded an algorithm to find cycles in an undirected graph with GAMS? If so, could you share it? Otherwise, any help is most welcome
Best regards
Fede
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Hello Claudio,
apparently, the best way to approach the problem is by means of the Depth-first search algorithm
Any idea on how to start?
Regards
Fede
On Mon, Mar 2, 2015 at 7:03 PM, Claudio Delpino wrote:
Fede: Hi, I would find that useful. So I offer my help to develop/test. Feel free to write me if you want to work together.
Regards
Claudio
On Thu, Feb 26, 2015 at 2:45 PM, Federico Perea wrote:
Dear GAMS users,
have you ever coded an algorithm to find cycles in an undirected graph with GAMS? If so, could you share it? Otherwise, any help is most welcome
Best regards
Fede
To unsubscribe from this group and stop receiving emails from it, send an email to gamsworld+unsubscribe@googlegroups.com.
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Fede,
Sometimes it’s easiest to move the data from GAMS to another environment and implement some data analysis there. Since depth-first-search (DFS) is quite simple when implemented recursively, I implemented a little code in R to return the number of connected components and the number of such components with cycles in them. The GAMS code and R script are attached.
To get this started I used our Data Utilities Model Library, specifically model invert1 from datalib. It contained all the GDX back and forth: I just changed the algorithmic details in the R script that came with the invert1 example. There are other examples in datalib relevant to Matlab, Excel, Access, etc., etc.
-Steve
On Mon, Mar 9, 2015 at 5:37 PM, Federico Perea wrote:
Hello Claudio,
apparently, the best way to approach the problem is by means of the Depth-first search algorithm
Any idea on how to start?
Regards
Fede
On Mon, Mar 2, 2015 at 7:03 PM, Claudio Delpino wrote:
Fede: Hi, I would find that useful. So I offer my help to develop/test. Feel free to write me if you want to work together.
Regards
Claudio
On Thu, Feb 26, 2015 at 2:45 PM, Federico Perea wrote:
Dear GAMS users,
have you ever coded an algorithm to find cycles in an undirected graph with GAMS? If so, could you share it? Otherwise, any help is most welcome
Best regards
Fede
–
cycleDetect.gms (813 Bytes)
cycleDetect.r (1.93 KB)
Hi
The r package igraph has an algorithm already implemented for the lazy among us… (Also dijkstra and so on)
Renger
Sent from my Samsung Note 4
-------- Original message --------
From: Steven Dirkse
Date: 10/03/2015 21:08 (GMT+01:00)
To: gamsworld@googlegroups.com
Subject: Re: find cycles in an undirected graph with GAMS
Fede,
Sometimes it’s easiest to move the data from GAMS to another environment and implement some data analysis there. Since depth-first-search (DFS) is quite simple when implemented recursively, I implemented a little code in R to return the number of connected components and the number of such components with cycles in them. The GAMS code and R script are attached.
To get this started I used our Data Utilities Model Library, specifically model invert1 from datalib. It contained all the GDX back and forth: I just changed the algorithmic details in the R script that came with the invert1 example. There are other examples in datalib relevant to Matlab, Excel, Access, etc., etc.
-Steve
On Mon, Mar 9, 2015 at 5:37 PM, Federico Perea wrote:
Hello Claudio,
apparently, the best way to approach the problem is by means of the Depth-first search algorithm
Any idea on how to start?
Regards
Fede
On Mon, Mar 2, 2015 at 7:03 PM, Claudio Delpino wrote:
Fede: Hi, I would find that useful. So I offer my help to develop/test. Feel free to write me if you want to work together.
Regards
Claudio
On Thu, Feb 26, 2015 at 2:45 PM, Federico Perea wrote:
Dear GAMS users,
have you ever coded an algorithm to find cycles in an undirected graph with GAMS? If so, could you share it? Otherwise, any help is most welcome
Best regards
Fede
Steven Dirkse, Ph.D.
GAMS Development Corp., Washington DC
Voice: (202)342-0180 Fax: (202)342-0181
sdirkse@gams.com
http://www.gams.com
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Thank you guys! I am not an r-user myself, but I will have a look at Steven code and see what I can get
Regards
Fede
On Tue, Mar 10, 2015 at 9:58 PM, Renger van Nieuwkoop wrote:
Hi
The r package igraph has an algorithm already implemented for the lazy among us… (Also dijkstra and so on)
Renger
Sent from my Samsung Note 4
-------- Original message --------
From: Steven Dirkse
Date: 10/03/2015 21:08 (GMT+01:00)
To: gamsworld@googlegroups.com
Subject: Re: find cycles in an undirected graph with GAMS
Fede,
Sometimes it’s easiest to move the data from GAMS to another environment and implement some data analysis there. Since depth-first-search (DFS) is quite simple when implemented recursively, I implemented a little code in R to return the number of connected components and the number of such components with cycles in them. The GAMS code and R script are attached.
To get this started I used our Data Utilities Model Library, specifically model invert1 from datalib. It contained all the GDX back and forth: I just changed the algorithmic details in the R script that came with the invert1 example. There are other examples in datalib relevant to Matlab, Excel, Access, etc., etc.
-Steve
On Mon, Mar 9, 2015 at 5:37 PM, Federico Perea wrote:
Hello Claudio,
apparently, the best way to approach the problem is by means of the Depth-first search algorithm
Any idea on how to start?
Regards
Fede
On Mon, Mar 2, 2015 at 7:03 PM, Claudio Delpino wrote:
Fede: Hi, I would find that useful. So I offer my help to develop/test. Feel free to write me if you want to work together.
Regards
Claudio
On Thu, Feb 26, 2015 at 2:45 PM, Federico Perea wrote:
Dear GAMS users,
have you ever coded an algorithm to find cycles in an undirected graph with GAMS? If so, could you share it? Otherwise, any help is most welcome
Best regards
Fede
Steven Dirkse, Ph.D.
GAMS Development Corp., Washington DC
Voice: (202)342-0180 Fax: (202)342-0181
sdirkse@gams.com
http://www.gams.com
–
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