tests/testthat/test_greedy_knapsack.R

In drowsygoat/lab6.knapsack: Solves Knapsack problem in three ways: brute force, dynamic programming and greedy approximation.

context("greedy_knapsack")

suppressWarnings(RNGversion(min(as.character(getRversion()),"3.5.3")))
set.seed(42, kind = "Mersenne-Twister", normal.kind = "Inversion")
n <- 2000
knapsack_objects <- data.frame(
        w=sample(1:4000, size = n, replace = TRUE),
        v=runif(n = n, 0, 10000)
)

test_that("Correct object is returned.", {
        expect_silent(gk <- greedy_knapsack(x = knapsack_objects[1:8,], W = 3500))
        expect_named(gk, c("value", "elements"))
})

test_that("Functions rejects errounous input.", {
        expect_error(greedy_knapsack("hej", 3500))
        expect_error(greedy_knapsack(x = knapsack_objects[1:8,], W = -3500))
})

test_that("Function return correct results.", {
        gk <- greedy_knapsack(x = knapsack_objects[1:8,], W = 3500)
        expect_equal(round(gk$value), 15773)
        expect_true(all(round(gk$elements) %in% c(6, 8)))

        gk <- greedy_knapsack(x = knapsack_objects[1:12,], W = 3500)
        expect_equal(round(gk$value), 15773)
        expect_true(all(round(gk$elements) %in% c(6, 8)))

        gk <- greedy_knapsack(x = knapsack_objects[1:8,], W = 2000)
        expect_equal(round(gk$value), 15428)
        expect_true(all(round(gk$elements) %in% c(3, 8)))

        gk <- greedy_knapsack(x = knapsack_objects[1:12,], W = 2000)
        expect_equal(round(gk$value), 15428)
        expect_true(all(round(gk$elements) %in% c(3, 8)))

        st <- system.time(gk <- greedy_knapsack(x = knapsack_objects[1:16,], W = 2000))
        expect_true(as.numeric(st)[2] <= 0.01)

        gk <- greedy_knapsack(x = knapsack_objects[1:800,], W = 3500)
        expect_equal(round(gk$value), 192647)

        gk <- greedy_knapsack(x = knapsack_objects[1:1200,], W = 3500)
        expect_equal(round(gk$value), 270290)
})