====== Topics ======

27. dec 2017

  Dragi Pat,
I am attaching the abstract with some changes included.

I am playing with the new option  '' Main Paths/Global search/Through vertices in cluster''

http://mrvar3.fdv.uni-lj.si/pajek/aa/Pajek503-32.exe

Some technical problems appeared because of very different weights in SPC nets. We can get cases where for a, b > 0

a + b = a
     
adding a very small positive number doesn't change the result:
<code>
> a <- 1
> b <- 1e-20
> c <- a+b
> c-a
[1] 0
</code>
A temporary solution is to use the logarithms of the weights. With Andrej, we will try to find a better solution. In the case of selected nodes from GeoPhysics island we get the attached main paths network - as expected, it doesn't link to the main main path - it belongs to another (main) topic.

**Question:** There can exist several main main paths in a given acyclic network. Develop an efficient algorithm that partition a network nodes/arcs according to the attraction main paths. 

  * https://en.wikipedia.org/wiki/Main_path_analysis
  * https://davincierlab.weebly.com/list-of-main-path-articles.html

An alternative approach:

  * http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.56.5220&rep=rep1&type=pdf
  *