The R Project SVN R-packages

if(!require(graph))
    q('no')
if(packageDescription("graph")$Version <= "1.10.2") {
    ## graph 1.10.x for x <= 2  had too much problems in  as(<graph>, "matrix")
    cat("Version of 'graph' is too old --- no tests done here!\n")
    q('no')
}

## else do things

library(Matrix)
if(FALSE)## for ease of developer:
    library(Matrix, lib="/u/maechler/R/Pkgs/Matrix.Rcheck")

example("graphNEL-class", echo = FALSE)
nodes(gR)

## 1) undirected
sm.g <- as(gR, "sparseMatrix")
str(sm.g)## 'dsT' - fine; even has Dimnames!
validObject(sm.g)
sm.g # should show the Dimnames - at least row ones

## 2) directed
gU <- gR; edgemode(gU) <- "directed"
sgU <- as(gU, "sparseMatrix")
str(sgU)## 'dgT' with dimnames
validObject(sgU)
sgU # should now show the Dimnames!

### Reverse :  sparseMatrix -> graph
if(FALSE) { ## not yet (FIXME!)
    gmg  <- as(sm.g, "graph")
    gmg2 <- as(sm.g, "graphNEL")
    gmgU <- as(sgU, "graph")
    gmgU <- as(sgU, "graphNEL")
}