Force Network: How to set initial position for select nodes?

[Tim Williams]

Hello everyone,

I have a simple force network graph of four nodes as an example, here:

https://jsfiddle.net/NovasTaylor/o1qesn6k/

I would like to set the initial position of node "A" using its accompanying data so the node is initially fixed at point (265,143) when I reload the graph. If I were to double-click that node it would return to being d.fixed=FALSE and the usual forces apply.

My larger goal is to fix key nodes of very large graphs. Other secondary nodes will not have x,y coordinates in their source data. I expect some logic similar to if d.init-x > 0 the fix the point at d.init-x, d.init-y   - but where do I put this code?

I wish to do this for ease of arranging the large graphs for presentation purposes, rather than having to manually drag these key nodes each time I reload the display.

I would greatly appreciate any insights you may have.

Tim

[Tim Williams]

Reading through the documentation online it appears I need to set the .x and .y for those nodes I wish to be static (at least initially).

If my data looks like this:

  var dataset = {
    "nodes":[
      {"id":0,"name":"A","group":"1", "fix_x":265, "fix_y":143},
      {"id":1,"name":"B","group":"2"},
      {"id":2,"name":"C","group":"3"},
      {"id":3,"name":"D","group":"4"}
      ],
    "edges":[
      {"source":0,"target":1,"value":""},
      {"source":1,"target":2,"value":""},
      {"source":2,"target":3,"value":""},
      {"source":3,"target":0,"value":""}
      ]
   }

I had hoped I could write something like this, but it does not appear to work. Any suggestions on where I am going wrong?

 for (var i=0,  tot=dataset.nodes.length; i < tot; i++) {
   // console.log("Node: " + dataset.nodes[i].name + " " + dataset.nodes[i].fix_x)
    if (dataset.nodes[i].fix_x > 0) {
      console.log("Found one!")
      dataset.nodes[i].x = dataset.nodes[i].fix_x
      dataset.nodes[i].y = dataset.nodes[i].fix_y
    }
  }

[Tim Williams]

Moved to Stackoverflow.

http://stackoverflow.com/questions/28816946/force-network-how-to-set-initial-position-for-select-nodes