VRP with GAMS

[Kumar]

Hi alI

We have GAMS & CPLEX software and want to solve VRP problem.Could
anybody send me any type of VRP problem.

Thanks

[A.L.]

Do it yourself. Use google. Start from here

http://neo.lcc.uma.es/radi-aeb/WebVRP/index.html

A.L.

[Kumar]

Thanks for the reply. Actually I know about this websites but nothing
has been mentioned about GAMS & CIPLEX. I am not good in programming so
wanted to solve the problem in aforesaid softwares.

[A.L.]

On 2 Oct 2006 08:53:09 -0700, "Kumar" <hkv...@gmail.com> wrote:

>Thanks for the reply. Actually I know about this websites but nothing
>has been mentioned about GAMS & CIPLEX. I am not good in programming so
>wanted to solve the problem in aforesaid softwares.

Maybe the reason why GAMS and CPLEX are not mentioned is that VRP is
not a linear programming problem. Actually, LP can be used on
various stages of solving process, but VRP is a bit more than LP.

Here is randomly selected link to materials that show where LP is
located within soem VRP solver.

http://www.cro-grid.hr/hr/apps/rep/app/oot/ESSCaSS04_s.pdf

Check also the book

The Vehicle Routing Problem Discrete Math (Siam Monographs on
Discrete Mathematics and Applications) by Paolo Toth , Daniele Vigo
This is the most up-to-date book on VRP and you will find a lot
about applicability of LP in various stages of solving VRP.

A.L>

[Kumar]

Thanks

[edgargutie...@gmail.com]

Hello,
I am student of industrial engineering , i need a guidance about Branch
and cut for the Capacited Vehicle Routing problem in GAMS.

Thanks a lot.

[A.L.]

On 19 Nov 2006 10:09:42 -0800, edgargutie...@gmail.com wrote:

>
>Hello,
>I am student of industrial engineering , i need a guidance about Branch
>and cut for the Capacited Vehicle Routing problem in GAMS.
>
>Thanks a lot.

Read discussion on GAMS and VRP that started 10/02/2006 under the
same subject

A.L.

[n.nashe...@gmail.com]

hi
i have a main problem about converting nonlinear vrp constraint to lineare one in gams ..

the following shows constraint i see in paper and write in gams, i want to make it linear in gams environment in order to solve it:


∑_(k=1)^K▒∑_(i=0)^N▒xI,j,k *(ti+ti,j + fi + wi) = tj J=1,2,…,N


cons(j)..sum((i,k),(t(i)+t(i,j)+f(i)+w(i))*x(i,j,k))=e=t(j);

is there anyone can help me on this issue???! if there is , my id is :nasim...@yahoo.com to get my answer

thanks
regard

[forogh.ta...@gmail.com]

hi, I have a VRP problem, could I send you?email?

[nazir...@gmail.com]

Hi there,
I'm working on VRP with time windows and the model that i write on Gams makes an error "Uncontrolled set entered as constant". So I need help urgently. Could anybody tell me reason of the problem? Model is as follows:

sets i customers/1,2,3,4,5,6,7/;
k vehicles/1,2,3,4/
Alias (i,j)


Table g(i,j) The total transportation and service time
0 1 2 3 4 5 6 7
0 100000 13.71 13.12 11.20 9.95 15.65 13.96 12.34
1 13.36 100000 0.97 2.47 3.40 2.56 0.89 1.52
2 12.82 1.02 100000 2.02 2.73 3.24 1.53 1.07
3 11.00 2.62 2.12 100000 3.85 4.27 2.78 1.21
4 9.55 3.35 2.63 3.65 100000 5.56 4.16 3.25
5 15.45 2.71 3.34 4.27 5.76 100000 2.02 3.89
6 13.76 1.04 1.63 2.78 4.36 2.02 100000 2.40
7 12.09 1.62 1.12 1.16 3.40 3.84 2.35 100000



binary variables X(i,j,k);
positive variables s(j,k);

time to start service at customer i (i,j) $((ord(i) ne (ord(j) and (ord(j) ne 1))))..s(i,k)-s(j,k)+sum(k,X(i,j,k))*10000=l=10000-g(i,j);

[osam...@gmail.com]

when you are mentioning S(i,k), its not sumed, neither mentioned in the beginning thats why ts saying that its uncontrolled. o you need to summ them on k as well.

[kapilg...@gmail.com]

Hello, Can you send me VRP sample code of GAMS software. I am at learning stage of GAMs, it will help me a lot and coding.

[anile...@gmail.com]

hocam aynı projeyi ben de yapıyorum da şuan bi şansımı denemek istedim. Eğer duruyorsa gams kodunu gönderebilir misin ?

[shiyua...@gmail.com]

forogh.t...@gmail.com於 2015年7月27日星期一 UTC-5下午12時31分10秒寫道：

Hi, I am also working on a VRP problem. Could you please share your code with me? I would be very grateful if you'd like to help me.

[lele]

Am Montag, 2. Oktober 2006 07:17:45 UTC+2 schrieb Kumar:
Hi
can someone send me the VRP GAMS Code? I just know the basics of GAMS so I would be very grateful if someone could help me.

> Thank you :)