d3.js: “Cannot read property 'weight' of undefined” when manually defining both nodes and links for force layout

Question

I tried setting both nodes and links at the same time this way:

var force = d3.layout.force()
    .size([w, h])
    .nodes(nodes)
    .links(connections)
            


        

Answer 1

The force-directed layout uses edge weights to calculate the layout. Try adding a dummy "weight":1 to all of your connections.

The code that initializes the links looks like this:

links.forEach(function(d) {
    if (typeof d.source == "number") { d.source = nodes[d.source]; }
    if (typeof d.target == "number") { d.target = nodes[d.target]; }
});

Presumably you could tweak that (in the d3 source) to use any property/type.