info about spring embedded layout

[IgnazioC]

i need to understand the cytoscape "spring embedded layout" what
determines the node position?
i tried the other layout, but "spring embedded" is the most
reppresentative of my graph. but i didn't understand why some nodes
are near and other are very far.
where can i find the specifics?

thanks

[Scooter Morris]

The Cytoscape spring embedded layout is an implementation of the
Kamada-Kawai algorithm (see Tomihisa Kamada, Satoru Kawai. An Algorithm
for Drawing General Undirected Graphs. Information Processing Letters,
31:7-15, 1988.). This approach models all edges as springs connecting
two nodes. Each spring has a "resting" length that it wants to be and a
strength. The algorithm then iterates over all of the springs and uses
a physics simulation to optimize the best length for each spring. Note
that in general, this is an n-dimensional problem, so when you force it
to optimize into two dimensions, you will get some springs (i.e. node
positions) that don't make sense.

-- scooter