```
# NOT RUN {
if(isTRUE(try(require(graph)))) { ## super careful .. for "checking reasons"
n4 <- LETTERS[1:4]; dns <- list(n4,n4)
show(a1 <- sparseMatrix(i= c(1:4), j=c(2:4,1), x = 2, dimnames=dns))
show(g1 <- as(a1, "graph")) # directed
unlist(edgeWeights(g1)) # all '2'
show(a2 <- sparseMatrix(i= c(1:4,4), j=c(2:4,1:2), x = TRUE, dimnames=dns))
show(g2 <- as(a2, "graph")) # directed
# now if you want it undirected:
show(g3 <- T2graph(as(a2,"TsparseMatrix"), edgemode="undirected"))
show(m3 <- as(g3,"Matrix"))
show( graph2T(g3) ) # a "pattern Matrix" (nsTMatrix)
# }
# NOT RUN {
a. <- sparseMatrix(i= 4:1, j=1:4, dimnames=list(n4,n4), giveC=FALSE) # no 'x'
show(a.) # "ngTMatrix"
show(g. <- as(a., "graph"))
# }
# NOT RUN {
}
# }
# NOT RUN {
<!-- % only if( graph ) -->
# }
```

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