warshall: Warshall's algorithm
In ssa: Singular Spectrum Analysis

Description Usage Arguments Value Note Author(s) References See Also Examples

View source: R/ssa.R

Warshall's algorithm to compute the transitive closure for an adjacency matrix.

1	warshall(a)

`a`	adjacency matrix

`a`	transitive closure of the relation corresponding to a

~~further notes~~

Patrick Crutcher

S. Warshal, A Theorem on Boolean Matrices. Journal of the Association of Computer Machinery, 9:11-12,1962

~~objects to See Also as help, ~~~

##---- Should be DIRECTLY executable !! ----
##-- ==>  Define data, use random,
##--	or do  help(data=index)  for the standard data sets.

## The function is currently defined as
function(a) {
n<-nrow(a)
for (j in 1:n) {
    for(i in 1:n) {
        if (a[i,j]==1) a[i,]<-pmax(a[i,],a[j,])
        }
    }
return(a)
}
{warshall}