[igraph] results of betweenness centrality and closeness centrality

[Jinie Pak]

I am currently using several SNA tools including R to analyze the data.  Eventually, I will use R because it can compute weighted network.
However, the results from R are different from other tools in terms of computing betweenness and closeness centralities.

In fact, the basic centrality scores from all tools are different except for the degree centrality.

I am just wondering what algorithm R uses for computing betweenness and closeness centrality.

I don’t expect R developers (experts) to know how other tools compute the centrality measures, but is there any possible explanation of why SNA tools produce different results?

I would like to know what causes this issue and any solution for this. 
Thank you! 

 

Jinie