CODEWITHSUNDEEP
gams-math
Richard
Richard

Reputation: 177

How can obtain it?

I have a set j and parameter edge. I have a graph too.

    Set j/1*5/;
   Alias(j,jp);

   Parameter edge(j,jp)

That edge(j,jp) =1 if there is arc from j to jp , and it's 0 if there isn't arc from j to jp. I maked edge(j,jp) .

I want to define a set or parameter , for saving index of neighborhood of node "j".

I Mean , neighborhood (j)={jp : edge(j,jp)=1}

I write ,below command but I get error.

  Set  neighborhood (j)
  Neighborhood (j)$edge (j,jp) =JP.val;

How can I obtain neighborhood of especial node?

Upvotes: 0

Views: 50

Answers (1)

Lutz
Lutz

Reputation: 2292

Do you work with an directed graph and assume there is just one neighbor for each j? Then, try this:

Set j/1*3/;
Alias(j,jp);

Parameter edge(j,jp) / 1.2 1, 2.3 1, 3.1 1 /;

Parameter Neighborhood (j);
Neighborhood (j) = sum(jp$edge(j,jp), jp.val);

Otherwise: What do you expect to see in Neighborhood, if there is more than one neighbor?

Upvotes: 1

Related Questions