directed-link-breed

directed-link-breed [<link-breeds> <link-breed>]

This keyword, like the globals and breeds keywords, can only be used at the beginning of the Code tab, before any procedure definitions. It defines a directed link breed. Links of a particular breed are always all directed or all undirected The first input defines the name of the agentset associated with the link breed. The second input defines the name of a single member of the breed. Directed links can be created using create-link(s)-to, and create-link(s)-from, but not create-link(s)-with

Any link of the given link breed:

• is part of the agentset named by the link breed name
• has its built-in variable breed set to that agentset
• is directed or undirected as declared by the keyword

Most often, the agentset is used in conjunction with ask to give commands to only the links of a particular breed.

directed-link-breed [streets street]
directed-link-breed [highways highway]
to setup
  clear-all
  crt 2
  ;; create a link from turtle 0 to turtle 1
  ask turtle 0 [ create-street-to turtle 1 ]
  ;; create a link from turtle 1 to turtle 0
  ask turtle 0 [ create-highway-from turtle 1 ]
end

ask turtle 0 [ show one-of my-in-links ]
;; prints (street 0 1)
ask turtle 0 [ show one-of my-out-links ]
;; prints (highway 1 0)

See also breed, undirected-link-breed