tests/testthat/test-covarToParameters.R

In primitybio/cellengine-r-toolkit: 'CellEngine' API Toolkit

context("covarToParameters")

test_that("returns ellipse parameters from covariance matrix", {
  covar <- matrix(c(6879, 3612, 3612, 5215),
    nrow = 2, ncol = 2, byrow = TRUE,
    dimnames = list(
      c("FSC-A", "FSC-W"),
      c("FSC-A", "FSC-W")
    )
  )
  params <- covarToParameters(covar)

  expect_equal(params$major, 98.8, tolerance = 0.001)
  expect_equal(params$minor, 48.4, tolerance = 0.001)
  expect_equal(params$angle, 0.672, tolerance = 0.001)
})

test_that("returns parameters for test matrix", {
  # https://cookierobotics.com/007/
  covar <- matrix(c(9, 5, 5, 4),
    nrow = 2, ncol = 2, byrow = TRUE,
    dimnames = list(
      c("FSC-A", "FSC-W"),
      c("FSC-A", "FSC-W")
    )
  )
  params <- covarToParameters(covar)

  expect_equal(params$major, 3.477, tolerance = 0.001)
  expect_equal(params$minor, 0.954, tolerance = 0.001)
  expect_equal(params$angle, 0.554, tolerance = 0.001)
})

test_that("returns ellipse parameters for a unit circle", {
  covar <- matrix(c(1, 0, 0, 1),
    nrow = 2, ncol = 2, byrow = TRUE,
    dimnames = list(
      c("FSC-A", "FSC-W"),
      c("FSC-A", "FSC-W")
    )
  )
  params <- covarToParameters(covar)

  expect_equal(params$major, 1, tolerance = 0.001)
  expect_equal(params$minor, 1, tolerance = 0.001)
  expect_equal(params$angle, 0, tolerance = 0.001)
})