GraphMakie distance between nodes

General Usage
1

Is there a way to adjust the distance between nodes? I have a simple graph like this that works:

begin
	g2 = cycle_digraph(3)
	fg=Figure(size=(800,800))
	axg=Axis(fg[1,1])
	GraphMakie.graphplot!(axg,g2;
	                     ilabels=[L"\,\,\,\mathrm{R}_i\,\,\,", L"\mathrm{R}_a", L"\mathrm{R}_r"], arrow_shift=:end,node_size=60,curve_distance=-.5, curve_distance_usage=true)
	hidedecorations!(axg); hidespines!(axg); 
	fg
end

I understand that I can manually specify node positions. It would be nice if I could specify some parameter to bring them closer (i.e. decrease edge lengths) rather than calculating the positions by hand each time. Is this possible?

2

The layout of the nodes in GraphMakie is determined by the layouts defined in NetworkLayouts.jl. I think you could play around with different layouts, the Stress layout for example supports a weights matrix which should influence the results.
Depending on your usecase you might want to look at the pin property available in several different layouts (e.g. Stress and Spring), which allows you to place a few vertices manually, while the layout will automatically place all the others.

3

Also, layouts are just functions which take a graph and return a list of positions. So sometimes it is usefull to just define your own layout which does some “postprocessing”. I.e.:

# define layout, which allways cuts the distance between nodes 7 and 8 in half
function mylayout(g)
    pos = NetworkLayout.stress(g) # get the initial layout based on your favorite layout algo
    # move vertices 7 and 8 closer together
    path = pos[8] - pos[7]
    pos[7] = pos[7] + 0.25 *path
    pos[8] = pos[8] - 0.25 *path
    return pos
end

graphplot(g; layout=mylayout)
4

Great, thank you! I’ll do some research into the various layouts.