Do as I command!

Not much to declare today; I have successfully retrieved some not-unattractive drawings from my contraction approximation, and it all runs in relatively fast time. Unfortunately, I am currently limited (runtime-wise) by the coarsening process which takes much longer in larger graphs (4elt, coarsener: 41sec fdp: 7sec).

I am therefore aiming to improve upon the coarsening technique so it is faster and uses less memory (as memory heap exceptions are also issues in huge graphs). I have still yet to determine whether the extended coarsening time is due to the calculation of the approximation structure (though it shouldn't be, I have to make sure).

Regarding Dynamics, I have thought it may be possible to introduce the multilevel paradigm into the contraction structure (as opposed to my current technique of running the FDP on each level) so to save some time (as the information is readily available to be calculated in the structure but needs to be applied correctly).

Back to my current implementation, the issues in lower levels of the graphs are still prevalent and I fear this is causing the algorithm to run longer than it needs to. I have managed to stop the vertices sticking to a tilted "plane" (I use the term loosely), achieved by using a random distance to push vertices apart as opposed to a set distance. I am currently working as to why the smaller graphs have such an issue, with the mostly likely suspect being inadequate forces.

Experimentation shows that changing the way the forces dampen the peripheral effect can lead to better or worse drawings based on the type of graph (grids benefit from a more power dampener).

It appears at the moment I have lots of little bits to play with; so I will look to mix these together or remove them as issues. For now, here are some more pretty pictures.

4elt.graph, although the peripheral effect is quite large, the structure of the graph can be easily identified.	fe_4elt2.graph, drawn with similar forces, the image shows the detail of the graph. Note; some areas of compression in the bottom where a section has folded on itself.
Hooray! Testing and achieved this odd looking drawing, seemingly of someone with hands in the air wearing a cape.I might just be going crazy though...	3elt.graph; unfortunately the layout here is quite flat, but till shows the layout of the graph with the compressed edges in the centre surrounding a gap.
55grid, drawn using the same forces used to draw the graph 4elt above, showing the forces do not necessarily work for all graphs. The difference is down to increasing the magnitude of the spring force, showing its relatively easy to alter the graph.