tests/testthat/test-ba.game.R

In igraph: Network Analysis and Visualization

test_that("sample_pa works", {
  g <- sample_pa(100, m = 2)
  expect_that(ecount(g), equals(197))
  expect_that(vcount(g), equals(100))
  expect_true(is_simple(g))

  g2 <- sample_pa(100, m = 2, algorithm = "psumtree-multiple")
  expect_that(ecount(g2), equals(198))
  expect_that(vcount(g2), equals(100))
  expect_false(is_simple(g2))

  g3 <- sample_pa(100, m = 2, algorithm = "bag")
  expect_that(ecount(g3), equals(198))
  expect_that(vcount(g3), equals(100))
  expect_false(is_simple(g3))
})

test_that("sample_pa can start from a graph", {
  set.seed(1234)

  g4 <- sample_pa(10, m = 1, algorithm = "bag", start.graph = make_empty_graph(5))
  expect_that(ecount(g4), equals(5))
  expect_that(vcount(g4), equals(10))
  expect_that(degree(g4), equals(c(2, 0, 0, 0, 1, 2, 1, 1, 2, 1)))

  g6 <- sample_pa(10, m = 1, algorithm = "bag", start.graph = make_star(10))
  expect_true(graph.isomorphic(g6, make_star(10)))

  g7 <- sample_pa(10,
    m = 3, algorithm = "psumtree-multiple",
    start.graph = make_empty_graph(5)
  )
  expect_that(degree(g7, mode = "out"), equals(c(0, 0, 0, 0, 0, 3, 3, 3, 3, 3)))

  g8 <- sample_pa(10,
    m = 3, algorithm = "psumtree-multiple",
    start.graph = make_star(5)
  )
  expect_that(degree(g8, mode = "out"), equals(c(0, 1, 1, 1, 1, 3, 3, 3, 3, 3)))
  expect_true(graph.isomorphic(induced_subgraph(g8, 1:5), make_star(5)))

  g9 <- sample_pa(10,
    m = 3, algorithm = "psumtree-multiple",
    start.graph = make_star(10)
  )
  expect_true(graph.isomorphic(g9, make_star(10)))

  g10 <- sample_pa(10, m = 3, start.graph = make_empty_graph(5))
  expect_that(degree(g10, mode = "out"), equals(c(0, 0, 0, 0, 0, 3, 3, 3, 3, 3)))

  g11 <- sample_pa(10, m = 3, start.graph = make_star(5))
  expect_that(degree(g11, mode = "out"), equals(c(0, 1, 1, 1, 1, 3, 3, 3, 3, 3)))
  expect_true(graph.isomorphic(induced_subgraph(g11, 1:5), make_star(5)))

  g12 <- sample_pa(10, m = 3, start.graph = make_star(10))
  expect_true(graph.isomorphic(g12, make_star(10)))
})