Hi,

I have to display a central node and the linked node around it. So I use the SpringLayout.

It works perfectly if I set a distance of 50.
But if I increase the distance to 200, the nodes are not well displayed: a part of the nodes are staying together.
I use: SpringLayout layout = new SpringLayout(1000, 200f, false, true);

What am i doing wrong ? Should I use another layout ?

Thanks,
Fabrice.

Hi Fabrice,

The problem is that the NodeDistance value is applied only as a desired length of links between connected nodes. Nodes that are not connected repulse each other with a force inversely proportional to the square of the distance, and we rely on this to get some symmetry. However this force becomes much weaker than the spring force when you change from 50 to 200, and the symmetry is lost. Now there is a RepulsionFactor attribute in the class, but it wasn't applied at all. You can find a fixed version on the private messages page; it now multiples the repulsion force that factor and you can get a symmetry at larger distances like this:

SpringLayout layout = new SpringLayout(1000, 200f, false, false);
layout.setRepulsionFactor(3000);
layout.setRandomSeed(10);
layout.arrange(diagram);
 

I hope that helps,
Stoyan