From 3aee2fd43e3059a699af2b63c6f2395e5a55e515 Mon Sep 17 00:00:00 2001 From: KatolaZ Date: Wed, 27 Sep 2017 15:06:31 +0100 Subject: First commit on github -- NetBunch 1.0 --- doc/kruskal.md | 89 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 89 insertions(+) create mode 100644 doc/kruskal.md (limited to 'doc/kruskal.md') diff --git a/doc/kruskal.md b/doc/kruskal.md new file mode 100644 index 0000000..b46e543 --- /dev/null +++ b/doc/kruskal.md @@ -0,0 +1,89 @@ +kruskal(1) -- Find the minimum/maximum spanning tree of a graph +====== + +## SYNOPSIS + +`kruskal` [MAX] + +## DESCRIPTION + +`kruskal` computes the minimum (or maximum) spanning tree of +, using the Kruskal's algorithm. If is +unweighted, `kruskal` computes one of the spanning trees of the +graph. The program prints on output the (weighted) edge list of the +spanning tree. + +## PARAMETERS + +* : + undirected input graph (edge list). It must be an existing file. + +* `MAX`: + If the second (optional) parameter is equal to `MAX`, compute the + maximum spanning tree. Otherwise, compute the minimum spanning tree. + +## OUTPUT + +The program prints on STDOUT the edge list of the minimum (maximum) +spannig tree of , in the format: + + i_1 j_1 w_ij_1 + i_2 j_2 w_ij_2 + .... + + +## EXAMPLES + +To find the minimum spanning tree of the graph `stocks_62_weight.net` +(the network of stocks in the New York Exchange market) we use the +command: + + $ kruskal stocks_62_weight.net + 52 53 0.72577357 + 43 53 0.72838212 + 2 53 0.72907212 + ... + 36 53 0.7973488 + 53 58 0.79931683 + 26 27 0.8029602 + $ + +which prints on output the edge list of the minimum spanning tree. +However, since the weight of each edge in that graph indicates the +similarity in the behaviour of two stocks, the maximum spanning tree +contains information about the backbone of similarities among +stocks. To obtain the maximum spannin tree, we just specify `MAX` as +second parameter: + + $ kruskal stocks_62_weight.net MAX + 56 58 1.523483 + 2 52 1.3826744 + 32 51 1.3812241 + ... + 33 55 0.86880272 + 7 28 0.8631584 + 1 53 0.81876166 + $ + +## SEE ALSO + +clust_w(1), dijkstra(1), largest_component(1) + +## REFERENCES + + +* J\. B. Kruskal. "On the shortest spanning subtree of a graph and the + traveling sales-man problem". P. Am. Math. Soc. 7 (1956), + 48-48. + +* V\. Latora, V. Nicosia, G. Russo, "Complex Networks: Principles, + Methods and Applications", Appendix 20, Cambridge University Press + (2017) + +* V\. Latora, V. Nicosia, G. Russo, "Complex Networks: Principles, + Methods and Applications", Chapter 10, Cambridge University Press + (2017) + +## AUTHORS + +(c) Vincenzo 'KatolaZ' Nicosia 2009-2017 ``. -- cgit v1.2.3