tests/testthat/test-divisor.R

In polettif/proporz: Proportional Apportionment

# http://www.wahlrecht.de/verfahren/dhondt123.html
test_that("divisor_floor", {
    v1 = c(4160, 3380, 2460)
    n1 = 10
    e1 = c(4L,4L,2L)
    expect_identical(divisor_floor(v1, n1), e1)
    expect_identical(proporz(v1, n1, "d'hondt"), e1)
    expect_identical(proporz(v1, n1, "jefferson"), e1)
})

# http://www.wahlrecht.de/verfahren/stlague12.html
test_that("divisor_round", {
    v2 = c(4160, 3380, 2460)
    n2 = 10
    e2 = c(4L,3L,3L)
    expect_identical(divisor_round(v2, n2), e2)
    expect_identical(proporz(v2, n2, "webster"), e2)
    expect_identical(proporz(v2, n2, "sainte-lague"), e2)
})

# https://de.wikipedia.org/wiki/Adams-Verfahren
test_that("divisor_ceiling", {
    v3 = c(450, 350, 199, 1)
    n3 = 50
    e3 = c(22L,17L,10L,1L)
    expect_identical(divisor_ceiling(v3, n3), e3)
    expect_identical(proporz(v3, n3, "adams"), e3)

    expect_identical(divisor_ceiling(c(1e-12, 0), 2), c(2L,0L))
    expect_identical(divisor_ceiling(c(0.1, 1e-12), 2), c(1L,1L))
    expect_identical(divisor_ceiling(c(1e13, 0), 2), c(2L,0L))
    expect_identical(divisor_ceiling(c(1e13, 1), 2), c(1L,1L))
})

# https://de.wikipedia.org/wiki/Adams-Verfahren
test_that("divisor_harmonic", {
    v4 = c(450, 350, 199, 1)
    n4 = 50
    e4 = c(22L,17L,10L,1L)
    expect_identical(divisor_harmonic(v4, n4), e4)
    expect_identical(proporz(v4, n4, "dean"), e4)

    expect_identical(divisor_harmonic(c(1e-12, 0), 2), c(2L,0L))
    expect_identical(divisor_harmonic(c(0.1, 1e-12), 2), c(1L,1L))
    expect_identical(divisor_harmonic(c(1e13, 0), 2), c(2L,0L))
    expect_identical(divisor_harmonic(c(1e13, 1), 2), c(1L,1L))
})

test_that("divisor_geometric", {
    # https://de.wikipedia.org/wiki/Hill-Huntington-Verfahren#H%C3%B6chstzahlverfahren
    v5 = c(450,350,199,1)
    n5 = 50
    e5 = c(22L,17L,10L,1L)
    expect_identical(divisor_geometric(v5, n5), e5)

    # https://en.wikipedia.org/wiki/Huntington%E2%80%93Hill_method#Example
    v6 = c(100,80,30,20)
    n6 = 8
    e6 = c(4L,3L,1L,0L)
    quor = sum(v6)/n6
    expect_identical(proporz(v6, n6, "huntington-hill", quor), e6)

    expect_identical(divisor_geometric(c(1e-12, 0), 2), c(2L,0L))
    expect_identical(divisor_geometric(c(0.1, 1e-12), 2), c(1L,1L))
    expect_identical(divisor_geometric(c(1e13, 0), 2), c(2L,0L))
    expect_identical(divisor_geometric(c(1e13, 1), 2), c(1L,1L))
})

test_that("compare", {
    # https://www.wahlrecht.de/verfahren/anschaulich/index.html
    v = c(43, 33, 12, 8, 4)

    expect_identical(divisor_ceiling(v, 10),  c(4L,3L,1L,1L,1L))
    expect_identical(divisor_geometric(v, 10),c(4L,3L,1L,1L,1L))
    expect_identical(divisor_harmonic(v, 10), c(4L,3L,1L,1L,1L))
    expect_identical(divisor_round(v, 10),    c(5L,3L,1L,1L,0L))
    expect_identical(divisor_floor(v, 10),    c(5L,4L,1L,0L,0L))
})

test_that("highest_averages_method", {
    expect_identical(highest_averages_method(c(5200, 1700, 3100), 15, 0.5), c(8L,2L,5L))
    expect_identical(highest_averages_method(c(100, 80, 30, 20), 8, 1), c(4L,3L,1L,0L))

    expect_error(highest_averages_method(c(100, 80, 30, 20), 3, c(0.5, 1.5)),
                 "Number of divisors is not equal to the number of seats")
})