This is part of a series of examples that describe the basic operation of the D3.js force layout. Eventually they may end up in a blog post that wraps everything together. If you missed the beginning of the series, here’s a link to first example.
An earlier example
introduced linkDistance as a key parameter for force layouts. It
sets the desired distance between any connected nodes. The force
layout includes an additional parameter that serves to modify the
linkDistance. That parameter is linkStrength. The default linkStrength
value is 1.0, which maintains the full effect of linkDistance.
By setting the value of linkStrength less than 1, though, the
distance constraint can be relaxed.
In this example the red link has a linkStrength of 0.1, while all the
other links retain the default value of 1.0. Use the controls in the
upper left to run the layout and see the effect of this reduced link
strength.
Note: the force that’s drawing the nodes together in this case is
gravity, which the next example considers in more detail. The links with a default strength are able to resist gravity more than the red link.