context("operators")
test_that("operators work", {
library(igraph)
o <- function(x) x[order(x[,1], x[,2]),]
g1 <- make_ring(10)
g2 <- make_star(11, center=11, mode="undirected")
gu <- union(g1, g2)
expect_that(vcount(gu), equals(11))
expect_that(ecount(gu), equals(20))
expect_that(o(rbind(as_edgelist(g1), as_edgelist(g2))),
equals(o(as_edgelist(gu))))
gdu <- disjoint_union(g1, g2)
expect_that(o(as_edgelist(gdu)),
equals(o(rbind(as_edgelist(g1),
as_edgelist(g2)+vcount(g1)))))
####
expect_true(graph.isomorphic(difference(gu, g1), g2))
####
expect_true(graph.isomorphic(intersection(gu, g2), g2))
expect_true(graph.isomorphic(intersection(gu, g1,
keep.all.vertices=FALSE),
g1))
####
x <- complementer(complementer(g2))
expect_true(identical_graphs(x, g2))
####
gc <- compose(gu, g1)
expect_that(vcount(gc), equals(11))
expect_that(ecount(gc), equals(60))
expect_that(diameter(gc), equals(2))
})
test_that("Union of directed named graphs", {
graphs <- list(
make_graph( ~1:2:3:4:5, 1-+2, 1-+3, 2-+3, 2-+4, 3-+4, 1-+5, 3-+5),
make_graph( ~1:2:3:4:5, 2-+3, 1-+4, 2-+4, 3-+4, 2-+5, 3-+5),
make_graph( ~1:2:3:4:5, 1-+2, 1-+3, 2-+4, 3-+4, 1-+5, 4-+5)
)
gg <- graph.union(graphs)
expect_equal(vcount(gg), 5)
expect_equal(ecount(gg), 10)
})
test_that("edge reversal works", {
# directed graph
g <- make_graph( ~ 1-+2, 1-+3, 1-+4, 2-+3, 3-+4 )
g2 <- reverse_edges(g, 1:3)
expected <- make_graph( ~ 1+-2, 1+-3, 1+-4, 2-+3, 3-+4 )
expect_true(isomorphic(g2, expected))
# undirected graph
g <- make_graph( ~ 1--2, 1--3, 1--4, 2--3, 3--4 )
g2 <- reverse_edges(g, 1:3)
expect_true(identical_graphs(g, g2))
# all edges
g <- make_graph( ~ 1-+2, 1-+3, 1-+4, 2-+3, 3-+4 )
g2 <- reverse_edges(g)
expect_that(vcount(g2), equals(vcount(g)))
expect_that(get.edgelist(g2), equals(get.edgelist(g)[,c(2,1)]))
# graph with isolated vertices
g <- make_graph( ~1:2:3:4:5, 1-+2, 1-+4 )
g2 <- reverse_edges(g)
expect_that(vcount(g2), equals(vcount(g)))
expect_that(get.edgelist(g2), equals(get.edgelist(g)[,c(2,1)]))
})
test_that("t() is aliased to edge reversal for graphs", {
g <- make_graph( ~ 1-+2, 1-+3, 1-+4, 2-+3, 3-+4 )
expect_that(vcount(t(g)), equals(vcount(g)))
expect_that(get.edgelist(t(g)), equals(get.edgelist(g)[,c(2,1)]))
})
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