Network Flow Data

GAMS
1

Hello,
I repeated this question in syntax section,
I wish to address set of paths to GAMS :nerd:
q Nodes on path q (in chronological order)
1 1,2,6,5,7,8,7,10,4,3,1
2 1,11,12,14,16,9,13,3,1
3 1,2,6,5,7,8,17,15,10,9,4,3,1
4 1,3,4,9,10,16,14,13,12,11,1
5 1,11,12,14,13,9,10,15,8,7,4,6,2,1

as it looks like some nodes are repeated in the route, and the routes are not same in size,
also i have to define these sets:
A Set of arcs of the transportation network
N Set of all vertices
A q Set of arcs existing on path q
N q Set of vertices existing on path q
Q Set of all paths
Q i Set of all paths passing vertex i
D Set of all dummy vertices
D i Set of dummy vertices for vertex i

dummy vertices are for visiting nodes for more than 1 time,

how can i define it in the model?

because i have to use some of these sets in equations in models, like in the sum on q$Q or i$(N U D)

please help me, :slight_smile:
best regards.
-Harry

2

Hi Harry
There are some nice models in the GAMS model library. For example, SROUTE, TRAFFIC. I would have a close look at the techniques they use (especially the mappings) to write down a network.
Cheers
Renger

3

Hi Mr. Renger,
Thanks for replying to me,

I also checked that models, but i didn’t find the assumptions that i want to include in. because in my modeling syntax, i have to enter data like dummy sets (visiting one node more than one time), nodes on path i ,…
and also I want to define a function to find the order of a vertex in a route, and use it as an index for some reasons,

by the way many thanks,
sincerely,
-Harry

4

hi
i have got same problem to defining sets.
please send your code of sets to me.
thank you very much indeed