tests/testthat/test-ramps.R

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context("Color ramps")

test_that("color_ramp_alpha is ok", {

  r1 <- colorRamp(c("red", "green"))( (0:4)/4 )
  r2 <- color_ramp_alpha(c("red", "green"))( (0:4)/4 )

  expect_equal(r1, r2[,1:3])
  expect_equal(r2[,4], rep(255, 5))

  r3 <- colorRamp(c("red", "green"), interpolate = "spline")( (0:4)/4 )
  r4 <- color_ramp_alpha(c("red", "green"), interpolate = "spline")( (0:4)/4 )

  expect_equal(r1, r2[,1:3])
  expect_equal(r2[,4], rep(255, 5))
})

test_that("color_ramp_alpha with single color", {
  r <- color_ramp_alpha ("red")(0:3 / 3)
  expect_equal(r[,1], rep(255, 4))
  expect_equal(r[,2], rep(0, 4))
  expect_equal(r[,3], rep(0, 4))
  expect_equal(r[,4], rep(255, 4))
})

test_that("color_ramp_palette_alpha is ok", {

  p1 <- colorRampPalette(c("blue", "red"))(4)
  p2 <- color_ramp_palette_alpha(c("blue", "red"))(4)

  expect_equal(paste0(p1, "FF"), p2)
})