test_that("Logarithmic distribution", { dist <- dist_logarithmic(0.66) expect_equal(format(dist), "Logarithmic(0.66)") # Require package installed skip_if_not_installed("actuar", "2.0.0") # quantiles expect_equal(quantile(dist, 0.5), actuar::qlogarithmic(0.5, 0.66)) expect_equal(quantile(dist, 0.99), actuar::qlogarithmic(0.99, 0.66)) # pdf expect_equal(density(dist, 1), actuar::dlogarithmic(1, 0.66)) expect_equal(density(dist, 9), actuar::dlogarithmic(9, 0.66)) # cdf expect_equal(cdf(dist, 3), actuar::plogarithmic(3, 0.66)) expect_equal(cdf(dist, 12), actuar::plogarithmic(12, 0.66)) # F(Finv(a)) ~= a expect_equal(cdf(dist, quantile(dist, 0.9963064)), 0.9963064, tolerance = 1e-3) # stats expect_equal(mean(dist), -1/log(1-0.66)*(0.66/(1-0.66))) expect_equal(variance(dist), -(0.66^2 + 0.66*log(1-0.66))/((1-0.66)^2*log(1-0.66)^2)) })