[SoC] GRASS - Network Analysis, 2nd week report

[Daniel Bundala]

Hello everyone,

While working on the module for computing articulation points, I found
a bug in the code calculating bridges. So the first real thing I did
this week was some bug fixing. Also, I have updated the module for
connected components so that it outputs the computed values in a more
useful way (Read: now it can be used for more than just producing nice
pictures to the first weak report....). Anyway, everything is kept in
a nice little database table. As the first sentence suggests, I have
done a module for computing articulation points in the networks.
Moreover, I have implemented a module that finds a minimum spanning
tree in the graph. This pictures shows both new modules in work: red
crosses are articulation points, green edges form a minimum spanning
tree (all edges have equal weight)
http://people.ksp.sk/~dano/grass/mstap.png. In the following picture,
the green edges also form a minimum spanning tree, but this time, the
speed limit is used as the weight of an edge. Note that the highway in
the centre is not included in the spanning tree:
http://people.ksp.sk/~dano/grass/mst.png. The latest version of the
code will appear shortly in the add-ons repository.

Currently, I cannot persuade the compiler to compile the library
correctly. So far, it does make cause any problems as no code is used
by two modules. I will look into this later next week and I will
probably start working on the family of modules using max-flows
algorithm as well.

 -Daniel