Consider any d3 force-directed animation, such as:

<http://bl.ocks.org/mbostock/1062288>

Load that graph and let the nodes settle down so that they are not moving. Hover your mouse over an orange node and let the mouse be still. Click and do nothing else. You will see all the nodes move inwards a little and then expand back to normal.

I do not like that unnecessary movement and I need to remove it.

I believe it has to do with the graph being "reheated" (see <https://github.com/mbostock/d3/wiki/Force-Layout>
), which sets the alpha parameter to 0.1. Specifically, I see the unnecessary movement occur immediately after any of the following.

1. a new node is added to the graph
2. a node is deleted from the graph
3. `force.drag()` is called.

What exactly causes this "unnecessary movement", and how can I disable it? (without disabling node dragging)