1
2context("mean_distance")
3
4test_that("mean_distance works", {
5  library(igraph)
6
7  apl <- function(graph) {
8    sp <- distances(graph, mode="out")
9    if (is_directed(graph)) {
10      diag(sp) <- NA
11    } else {
12      sp[lower.tri(sp, diag=TRUE)] <- NA
13    }
14    sp[sp=="Inf"] <- NA
15    mean(sp, na.rm=TRUE)
16  }
17
18  giant.component <- function(graph, mode="weak") {
19    clu <- components(graph, mode=mode)
20    induced_subgraph(graph, which(clu$membership==which.max(clu$csize)))
21  }
22
23  g <- giant.component(sample_gnp(100, 3/100))
24  expect_that(apl(g), equals(mean_distance(g)))
25
26  g <- giant.component(sample_gnp(100, 6/100, dir=TRUE), mode="strong")
27  expect_that(apl(g), equals(mean_distance(g)))
28
29  g <- sample_gnp(100, 2/100)
30  expect_that(apl(g), equals(mean_distance(g)))
31
32  g <- sample_gnp(100, 4/100, dir=TRUE)
33  expect_that(apl(g), equals(mean_distance(g)))
34})
35