test_that("prox_sorted_L1 agrees with isotone package", { if (!requireNamespace("isotone", quietly = TRUE)) skip("isotone package not available") n <- 20 mu <- 1.5 * (n:1) y <- sort(abs(rnorm(n, mean = mu)), decreasing = TRUE) lambda <- n:1 expect_equal(prox_sorted_L1_C(y, lambda), prox_sorted_L1_isotone(y, lambda)) })