test_that("OPTICS-XI", {
  load(system.file("test_data/test_data.rda", package = "dbscan"))
  load(system.file("test_data/elki_optics.rda", package = "dbscan"))
  load(system.file("test_data/elki_optics_xi.rda", package = "dbscan"))

  ### run OPTICS XI with parameters: xi=0.01, eps=1.0, minPts=5
  x <- test_data
  res <- optics(x, eps = 1.0,  minPts = 5)
  res <- extractXi(res, xi=0.10, minimum=FALSE)

  ### Check to make sure ELKI results match R
  expected <- res$clusters_xi[, c("start", "end")]
  class(expected) <- "data.frame"
  expect_identical(elki_optics_xi, expected)
})