d3-force-troubleshooting

Common problems I've had when building force-directed diagrams in d3.

• Nodes ignore force completely and appear in top left corner, overlapping.
• You may have duplicate links. You can have multiple links between nodes but they need unique names.
• It may also be a problem with the link ids.
• Did you start the force simulation?
• This also happens when the nodes are not updated correctly. (I had nodeEnter.merge(node) instead of node = nodeEnter.merge(node))
• Nodes are linked but ignore charge, so that all neighbor nodes 'collapse' and overlap with one another.
• Do you have a custom charge() function? It might be broken.
• Nodes are arranged and linked together correctly but links don't show up.
• Are the links formatted correctly (e.g. in CSS)? (and does their class match and all that)