test_that("Power centrality works", {
  ## Generate some test data from Bonacich, 1987:
  fig1 <- graph_from_literal(A - +B - +C:D)
  fig1.bp <- lapply(seq(0, 0.8, by = 0.2), function(x) {
    round(power_centrality(fig1, exponent = x), 2)
  })
  expect_equal(fig1.bp, list(c(A = 0.89, B = 1.79, C = 0, D = 0), c(A = 1.15, B = 1.64, C = 0, D = 0), c(A = 1.34, B = 1.49, C = 0, D = 0), c(A = 1.48, B = 1.35, C = 0, D = 0), c(A = 1.59, B = 1.22, C = 0, D = 0)))

  g.c <- make_graph(c(1, 2, 1, 3, 2, 4, 3, 5), dir = FALSE)
  bp.c <- lapply(seq(-.5, .5, by = 0.1), function(x) {
    round(power_centrality(g.c, exponent = x), 2)[c(1, 2, 4)]
  })

  expect_equal(bp.c, list(c(0.00, 1.58, 0.00), c(0.73, 1.45, 0.36), c(0.97, 1.34, 0.49), c(1.09, 1.27, 0.54), c(1.15, 1.23, 0.58), c(1.20, 1.20, 0.60), c(1.22, 1.17, 0.61), c(1.25, 1.16, 0.62), c(1.26, 1.14, 0.63), c(1.27, 1.13, 0.64), c(1.28, 1.12, 0.64)))

  g.d <- make_graph(c(1, 2, 1, 3, 1, 4, 2, 5, 3, 6, 4, 7), dir = FALSE)
  bp.d <- lapply(seq(-.4, .4, by = 0.1), function(x) {
    round(power_centrality(g.d, exponent = x), 2)[c(1, 2, 5)]
  })
  expect_equal(bp.d, list(c(1.62, 1.08, 0.54), c(1.62, 1.08, 0.54), c(1.62, 1.08, 0.54), c(1.62, 1.08, 0.54), c(1.62, 1.08, 0.54), c(1.62, 1.08, 0.54), c(1.62, 1.08, 0.54), c(1.62, 1.08, 0.54), c(1.62, 1.08, 0.54)))

  g.e <- make_graph(c(1, 2, 1, 3, 1, 4, 2, 5, 2, 6, 3, 7, 3, 8, 4, 9, 4, 10), dir = FALSE)
  bp.e <- lapply(seq(-.4, .4, by = 0.1), function(x) {
    round(power_centrality(g.e, exponent = x), 2)[c(1, 2, 5)]
  })
  expect_equal(bp.e, list(c(-1.00, 1.67, -0.33), c(0.36, 1.81, 0.12), c(1.00, 1.67, 0.33), c(1.30, 1.55, 0.43), c(1.46, 1.46, 0.49), c(1.57, 1.40, 0.52), c(1.63, 1.36, 0.54), c(1.68, 1.33, 0.56), c(1.72, 1.30, 0.57)))

  g.f <- make_graph(c(1, 2, 1, 3, 1, 4, 2, 5, 2, 6, 2, 7, 3, 8, 3, 9, 3, 10, 4, 11, 4, 12, 4, 13),
    dir = FALSE
  )
  bp.f <- lapply(seq(-.4, .4, by = 0.1), function(x) {
    round(power_centrality(g.f, exponent = x), 2)[c(1, 2, 5)]
  })
  expect_equal(
    bp.f,
    list(c(-1.72, 1.53, -0.57), c(-0.55, 2.03, -0.18), c(0.44, 2.05, 0.15), c(1.01, 1.91, 0.34), c(1.33, 1.78, 0.44), c(1.52, 1.67, 0.51), c(1.65, 1.59, 0.55), c(1.74, 1.53, 0.58), c(1.80, 1.48, 0.60))
  )
})