relation4gn: formats the arc of a gn from a relation matrix
In g4n: graph for networks

Description Usage Arguments Details Value Examples

From a completely described gn and a matrix of scores between all nodes of it, modifies the format of the arcs to take into account the strength of their relations.

1	relation4gn(gn, rel, cl="equal")

`gn`	The gn to be modified.
`rel`	The matrix of scores for the relationships. It is a non symmetric matrix, rows are considered parents of the columns.
`cl`	(='equal') See the details section.

(1) No arcs are added, only existing arcs are considered.
(2) The set of existing arcs is categorized into four classes : poor (dashed), small (continuous 1), medium (continuous 2) and strong (continuous 3).
(3) The classes are defined with three limits defined by cl. cl = 'equal' divides the arcs into approximately four equally numbered categories. cl = 'propto' divides the range of categories into four equal scaled categories. cl = numeric(3) imposed the three limit to use.
(4) NA valued arcs by rel are valued as the "minimum - 1" before determining the categories.

The modified gn

 g4n3k("RESET"); # needed only for R checking, to be forgotten
 g0 <- g4n.gn7; 
 nbn <- nbnv(g0, g0@item); 
 gg <- relation4gn(g0, matrix(1:nbn^2, nbn));