nw:get-context

nw:get-context

Reports the content of the current graph context as a list containing two agentsets: the agentset of turtles that are part of the context and the agentset of links that are part of the context.

Let’s say we start with a blank slate and the default context consisting of turtles and links, nw:get-context will report a list the special turtles and links breed agentsets:

observer> clear-all
observer> show nw:get-context
observer: [turtles links]

If we add some turtles and links to our context, we’ll still see the same thing, even though turtles and links have internally grown:

observer> crt 2 [ create-links-with other turtles ]
observer> show nw:get-context
observer: [turtles links]

If you had set your context to normal agentsets instead (built with turtle-set, link-set or with) here is what you would see:

observer> clear-all
observer> nw:set-context turtle-set turtles link-set links
observer> show nw:get-context
observer: [(agentset, 0 turtles) (agentset, 0 links)]

If you then create new turtles and links, they are not added to the context because normal agentsets don’t grow (see Special agentsets vs normal agentsets):

observer> crt 2 [ create-links-with other turtles ]
observer> show nw:get-context
observer: [(agentset, 0 turtles) (agentset, 0 links)]

But if you construct new agentsets and set the context to them, your new agents will be there:

observer> nw:set-context turtle-set turtles link-set links
observer> show nw:get-context
observer: [(agentset, 2 turtles) (agentset, 1 link)]

If you want to see the actual content of your context, it is easy to turn your agentsets into lists that can be nicely displayed. Just use a combination of map and sort:

observer> show map sort nw:get-context
observer: [[(turtle 0) (turtle 1)] [(link 0 1)]]

Finally, you can use nw:get-context to store a context that you eventually want to restore:

extensions [ nw ]
to store-and-restore-context
  clear-all
  crt 2 [
    set color red
    create-links-with other turtles with [ color = red ] [
      set color yellow
    ]
  ]
  crt 2 [
    set color blue
    create-links-with other turtles with [ color = blue ] [
      set color green
    ]
  ]
  nw:set-context turtles with [ color = red ] links with [ color = yellow ]
  show map sort nw:get-context
  let old-turtles item 0 nw:get-context
  let old-links item 1 nw:get-context
  nw:set-context turtles with [ color = blue ] links with [ color = green ]
  show map sort nw:get-context
  nw:set-context old-turtles old-links
  show map sort nw:get-context
end

Here is the result:

observer> store-and-restore-context
observer: [[(turtle 0) (turtle 1)] [(link 0 1)]]
observer: [[(turtle 2) (turtle 3)] [(link 2 3)]]
observer: [[(turtle 0) (turtle 1)] [(link 0 1)]]