If I understand you correctly, you want to have a central node, with connected nodes in a circle around it. Something like this command will arrange the nodes around the selected node:
[code] GoNode parent = myView.Selection.Primary as GoNode;
if (parent != null) {
int num = 0;
foreach (IGoNode c in parent.Nodes) num++;
if (num > 0) {
PointF center = parent.Center;
int i = 0;
float radius = 150;
double angle = Math.PI*2/num;
foreach (IGoNode c in parent.Nodes) {
c.GoObject.Center = new PointF(center.X + radius * (float)Math.Cos(i * angle),
center.Y + radius * (float)Math.Sin(i * angle));
i++;
}
}
}[/code]