v/vlib/rand/mt19937/mt19937_test.v

333 lines
7.5 KiB
V

import math
import rand
import rand.mt19937
import rand.seed
const (
range_limit = 40
value_count = 1000
seeds = [[u32(0xcafebabe), u32(0xdeadbeef)], [u32(0xc0de), u32(0xfeed)]]
)
const (
sample_size = 1000
stats_epsilon = 0.05
inv_sqrt_12 = 1.0 / math.sqrt(12)
)
fn mt19937_basic_test() {
mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
rng.seed([u32(0xdeadbeef)])
target := [u32(956529277), 3842322136, 3319553134, 1843186657, 2704993644, 595827513, 938518626,
1676224337, 3221315650, 1819026461]
for i := 0; i < 10; i++ {
assert target[i] == rng.u32()
}
}
fn gen_randoms(seed_data []u32, bound int) []u64 {
bound_u64 := u64(bound)
mut randoms := []u64{len: (20)}
x := mt19937.MT19937RNG{}
mut rnd := rand.PRNG(x)
rnd.seed(seed_data)
for i in 0 .. 20 {
randoms[i] = rnd.u64n(bound_u64) or { panic("Couldn't obtain random u64") }
}
return randoms
}
fn test_mt19937_reproducibility() {
seed_data := seed.time_seed_array(2)
randoms1 := gen_randoms(seed_data, 1000)
randoms2 := gen_randoms(seed_data, 1000)
assert randoms1.len == randoms2.len
len := randoms1.len
for i in 0 .. len {
assert randoms1[i] == randoms2[i]
}
}
fn test_mt19937_variability() {
// If this test fails and if it is certainly not the implementation
// at fault, try changing the seed values. Repeated values are
// improbable but not impossible.
for seed in seeds {
mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
rng.seed(seed)
mut values := []u64{cap: value_count}
for i in 0 .. value_count {
value := rng.u64()
assert value !in values
assert values.len == i
values << value
}
}
}
fn check_uniformity_u64(mut rng rand.PRNG, range u64) {
range_f64 := f64(range)
expected_mean := range_f64 / 2.0
mut variance := 0.0
for _ in 0 .. sample_size {
diff := f64(rng.u64n(range) or { panic("Couldn't obtain random u64") }) - expected_mean
variance += diff * diff
}
variance /= sample_size - 1
sigma := math.sqrt(variance)
expected_sigma := range_f64 * inv_sqrt_12
error := (sigma - expected_sigma) / expected_sigma
assert math.abs(error) < stats_epsilon
}
fn test_mt19937_uniformity_u64() {
ranges := [14019545, 80240, 130]
for seed in seeds {
mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
rng.seed(seed)
for range in ranges {
check_uniformity_u64(mut rng, u64(range))
}
}
}
fn check_uniformity_f64(mut rng rand.PRNG) {
expected_mean := 0.5
mut variance := 0.0
for _ in 0 .. sample_size {
diff := rng.f64() - expected_mean
variance += diff * diff
}
variance /= sample_size - 1
sigma := math.sqrt(variance)
expected_sigma := inv_sqrt_12
error := (sigma - expected_sigma) / expected_sigma
assert math.abs(error) < stats_epsilon
}
fn test_mt19937_uniformity_f64() {
// The f64 version
for seed in seeds {
mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
rng.seed(seed)
check_uniformity_f64(mut rng)
}
}
fn test_mt19937_u32n() {
max := u32(16384)
for seed in seeds {
mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
rng.seed(seed)
for _ in 0 .. range_limit {
value := rng.u32n(max) or { panic("Couldn't obtain random u32") }
assert value >= 0
assert value < max
}
}
}
fn test_mt19937_u64n() {
max := u64(379091181005)
for seed in seeds {
mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
rng.seed(seed)
for _ in 0 .. range_limit {
value := rng.u64n(max) or { panic("Couldn't obtain random u64") }
assert value >= 0
assert value < max
}
}
}
fn test_mt19937_u32_in_range() {
max := u32(484468466)
min := u32(316846)
for seed in seeds {
mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
rng.seed(seed)
for _ in 0 .. range_limit {
value := rng.u32_in_range(min, max) or { panic("Couldn't obtain random u32 in range.") }
assert value >= min
assert value < max
}
}
}
fn test_mt19937_u64_in_range() {
max := u64(216468454685163)
min := u64(6848646868)
for seed in seeds {
mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
rng.seed(seed)
for _ in 0 .. range_limit {
value := rng.u64_in_range(min, max) or { panic("Couldn't obtain random u64 in range.") }
assert value >= min
assert value < max
}
}
}
fn test_mt19937_int31() {
max_u31 := int(0x7FFFFFFF)
sign_mask := int(0x80000000)
for seed in seeds {
mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
rng.seed(seed)
for _ in 0 .. range_limit {
value := rng.int31()
assert value >= 0
assert value <= max_u31
// This statement ensures that the sign bit is zero
assert (value & sign_mask) == 0
}
}
}
fn test_mt19937_int63() {
max_u63 := i64(0x7FFFFFFFFFFFFFFF)
sign_mask := i64(0x8000000000000000)
for seed in seeds {
mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
rng.seed(seed)
for _ in 0 .. range_limit {
value := rng.int63()
assert value >= 0
assert value <= max_u63
assert (value & sign_mask) == 0
}
}
}
fn test_mt19937_intn() {
max := 2525642
for seed in seeds {
mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
rng.seed(seed)
for _ in 0 .. range_limit {
value := rng.intn(max) or { panic("Couldn't obtain random int") }
assert value >= 0
assert value < max
}
}
}
fn test_mt19937_i64n() {
max := i64(3246727724653636)
for seed in seeds {
mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
rng.seed(seed)
for _ in 0 .. range_limit {
value := rng.i64n(max) or { panic("Couldn't obtain random i64") }
assert value >= 0
assert value < max
}
}
}
fn test_mt19937_int_in_range() {
min := -4252
max := 1034
for seed in seeds {
mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
rng.seed(seed)
for _ in 0 .. range_limit {
value := rng.int_in_range(min, max) or { panic("Couldn't obtain random int in range.") }
assert value >= min
assert value < max
}
}
}
fn test_mt19937_i64_in_range() {
min := i64(-24095)
max := i64(324058)
for seed in seeds {
mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
rng.seed(seed)
for _ in 0 .. range_limit {
value := rng.i64_in_range(min, max) or { panic("Couldn't obtain random i64 in range.") }
assert value >= min
assert value < max
}
}
}
fn test_mt19937_f32() {
for seed in seeds {
mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
rng.seed(seed)
for _ in 0 .. range_limit {
value := rng.f32()
assert value >= 0.0
assert value < 1.0
}
}
}
fn test_mt19937_f64() {
for seed in seeds {
mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
rng.seed(seed)
for _ in 0 .. range_limit {
value := rng.f64()
assert value >= 0.0
assert value < 1.0
}
}
}
fn test_mt19937_f32n() {
max := f32(357.0)
for seed in seeds {
mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
rng.seed(seed)
for _ in 0 .. range_limit {
value := rng.f32n(max) or { panic("Couldn't obtain random f32") }
assert value >= 0.0
assert value < max
}
}
}
fn test_mt19937_f64n() {
max := 1.52e6
for seed in seeds {
mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
rng.seed(seed)
for _ in 0 .. range_limit {
value := rng.f64n(max) or { panic("Couldn't obtain random f64") }
assert value >= 0.0
assert value < max
}
}
}
fn test_mt19937_f32_in_range() {
min := f32(-24.0)
max := f32(125.0)
for seed in seeds {
mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
rng.seed(seed)
for _ in 0 .. range_limit {
value := rng.f32_in_range(min, max) or { panic("Couldn't obtain random f32 in range.") }
assert value >= min
assert value < max
}
}
}
fn test_mt19937_f64_in_range() {
min := -548.7
max := 5015.2
for seed in seeds {
mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
rng.seed(seed)
for _ in 0 .. range_limit {
value := rng.f64_in_range(min, max) or { panic("Couldn't obtain random f64 in range.") }
assert value >= min
assert value < max
}
}
}