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Diffstat (limited to 'tests/stdlib/trandom.nim')
| -rw-r--r-- | tests/stdlib/trandom.nim | 310 |
1 files changed, 310 insertions, 0 deletions
diff --git a/tests/stdlib/trandom.nim b/tests/stdlib/trandom.nim new file mode 100644 index 000000000..eb32f7757 --- /dev/null +++ b/tests/stdlib/trandom.nim @@ -0,0 +1,310 @@ +discard """ + joinable: false # to avoid messing with global rand state + matrix: "--mm:refc; --mm:orc; --backend:js --jsbigint64:off -d:nimStringHash2; --backend:js --jsbigint64:on" +""" +import std/[assertions, formatfloat] +import std/[random, math, stats, sets, tables] +import std/private/jsutils +when not defined(js): + import std/os + +randomize(233) + +proc main() = + var occur: array[1000, int] + + for i in 0..100_000: + let x = rand(high(occur)) + inc occur[x] + + doAssert max(occur) <= 140 and min(occur) >= 60 # gives some slack + + var a = [0, 1] + shuffle(a) + doAssert a in [[0,1], [1,0]] + + doAssert rand(0) == 0 + when not defined(nimscript): + doAssert sample("a") == 'a' + + when compileOption("rangeChecks") and not defined(nimscript): + doAssertRaises(RangeDefect): + discard rand(-1) + + doAssertRaises(RangeDefect): + discard rand(-1.0) + + # don't use causes integer overflow + doAssert compiles(rand[int](low(int) .. high(int))) + +main() + +block: + when not defined(js): + doAssert almostEqual(rand(12.5), 7.355175342026979) + doAssert almostEqual(rand(2233.3322), 499.342386778917) + + type DiceRoll = range[0..6] + when not defined(js): + doAssert rand(DiceRoll).int == 3 + elif compileOption("jsbigint64"): + doAssert rand(DiceRoll).int == 1 + else: + doAssert rand(DiceRoll).int == 6 + +var rs: RunningStat +for j in 1..5: + for i in 1 .. 100_000: + rs.push(gauss()) + doAssert abs(rs.mean-0) < 0.08, $rs.mean + doAssert abs(rs.standardDeviation()-1.0) < 0.1 + let bounds = [3.5, 5.0] + for a in [rs.max, -rs.min]: + doAssert a >= bounds[0] and a <= bounds[1] + rs.clear() + +block: + type DiceRoll = range[3..6] + var flag = false + for i in 0..<100: + if rand(5.DiceRoll) < 3: + flag = true + doAssert flag # because of: rand(max: int): int + + +block: # random int + block: # there might be some randomness + var set = initHashSet[int](128) + + for i in 1..1000: + incl(set, rand(high(int))) + doAssert len(set) == 1000 + + block: # single number bounds work + var rand: int + for i in 1..1000: + rand = rand(1000) + doAssert rand <= 1000 + doAssert rand >= 0 + + block: # slice bounds work + var rand: int + for i in 1..1000: + rand = rand(100..1000) + doAssert rand <= 1000 + doAssert rand >= 100 + + block: # again gives new numbers + var rand1 = rand(1000000) + when not (defined(js) or defined(nimscript)): + os.sleep(200) + + var rand2 = rand(1000000) + doAssert rand1 != rand2 + +block: # random float + block: # there might be some randomness + var set = initHashSet[float](128) + + for i in 1..100: + incl(set, rand(1.0)) + doAssert len(set) == 100 + + block: # single number bounds work + var rand: float + for i in 1..1000: + rand = rand(1000.0) + doAssert rand <= 1000.0 + doAssert rand >= 0.0 + + block: # slice bounds work + var rand: float + for i in 1..1000: + rand = rand(100.0..1000.0) + doAssert rand <= 1000.0 + doAssert rand >= 100.0 + + block: # again gives new numbers + var rand1: float = rand(1000000.0) + when not (defined(js) or defined(nimscript)): + os.sleep(200) + + var rand2: float = rand(1000000.0) + doAssert rand1 != rand2 + +block: # random sample + block: # "non-uniform array sample unnormalized int CDF + let values = [10, 20, 30, 40, 50] # values + let counts = [4, 3, 2, 1, 0] # weights aka unnormalized probabilities + var histo = initCountTable[int]() + let cdf = counts.cumsummed # unnormalized CDF + for i in 0 ..< 5000: + histo.inc(sample(values, cdf)) + doAssert histo.len == 4 # number of non-zero in `counts` + # Any one bin is a binomial random var for n samples, each with prob p of + # adding a count to k; E[k]=p*n, Var k=p*(1-p)*n, approximately Normal for + # big n. So, P(abs(k - p*n)/sqrt(p*(1-p)*n))>3.0) =~ 0.0027, while + # P(wholeTestFails) =~ 1 - P(binPasses)^4 =~ 1 - (1-0.0027)^4 =~ 0.01. + for i, c in counts: + if c == 0: + doAssert values[i] notin histo + continue + let p = float(c) / float(cdf[^1]) + let n = 5000.0 + let expected = p * n + let stdDev = sqrt(n * p * (1.0 - p)) + doAssert abs(float(histo[values[i]]) - expected) <= 3.0 * stdDev + + block: # non-uniform array sample normalized float CDF + let values = [10, 20, 30, 40, 50] # values + let counts = [0.4, 0.3, 0.2, 0.1, 0] # probabilities + var histo = initCountTable[int]() + let cdf = counts.cumsummed # normalized CDF + for i in 0 ..< 5000: + histo.inc(sample(values, cdf)) + doAssert histo.len == 4 # number of non-zero in ``counts`` + for i, c in counts: + if c == 0: + doAssert values[i] notin histo + continue + let p = float(c) / float(cdf[^1]) + let n = 5000.0 + let expected = p * n + let stdDev = sqrt(n * p * (1.0 - p)) + # NOTE: like unnormalized int CDF test, P(wholeTestFails) =~ 0.01. + doAssert abs(float(histo[values[i]]) - expected) <= 3.0 * stdDev + +block: + # 0 is a valid seed + var r = initRand(0) + doAssert r.rand(1.0) != r.rand(1.0) + r = initRand(10) + doAssert r.rand(1.0) != r.rand(1.0) + # changing the seed changes the sequence + var r1 = initRand(123) + var r2 = initRand(124) + doAssert r1.rand(1.0) != r2.rand(1.0) + +block: # bug #17467 + let n = 1000 + for i in -n .. n: + var r = initRand(i) + let x = r.rand(1.0) + doAssert x > 1e-4, $(x, i) + # This used to fail for each i in 0..<26844, i.e. the 1st produced value + # was predictable and < 1e-4, skewing distributions. + +block: # bug #16360, Natural overload + var r = initRand() + template test(a) = + let a2 = a + block: + let a3 = r.rand(a2) + doAssert a3 <= a2 + doAssert a3.type is a2.type + block: + let a3 = rand(a2) + doAssert a3 <= a2 + doAssert a3.type is a2.type + test int.high + test int.high - 1 + test int.high - 2 + test 0 + +block: # same as above but use slice overload + var r = initRand() + template test[T](a: T) = + let a2: T = a + block: + let a3 = r.rand(T(0) .. a2) + doAssert a3 <= a2 + doAssert a3.type is a2.type + block: + let a3 = rand(T(0) .. a2) + doAssert a3 <= a2 + doAssert a3.type is a2.type + test cast[uint](int.high) + test cast[uint](int.high) + 1 + whenJsNoBigInt64: discard + do: + test uint64.high + test uint64.high - 1 + test uint.high - 2 + test uint.high - 1 + test uint.high + test int.high + test int.high - 1 + test int.high - 2 + test 0 + test 0'u + test 0'u64 + +block: # bug #16296 + var r = initRand() + template test(x) = + let a2 = x + let a3 = r.rand(a2) + doAssert a3 <= a2.b + doAssert a3 >= a2.a + doAssert a3.type is a2.a.type + test(-2 .. int.high-1) + test(int.low .. int.high) + test(int.low+1 .. int.high) + test(int.low .. int.high-1) + test(int.low .. 0) + test(int.low .. -1) + test(int.low .. 1) + test(int64.low .. 1'i64) + test(10'u64 .. uint64.high) + +block: # bug #17670 + type UInt48 = range[0'u64..2'u64^48-1] + let x = rand(UInt48) + doAssert x is UInt48 + +block: # bug #17898 + # Checks whether `initRand()` generates unique states. + # size should be 2^64, but we don't have time and space. + + # Disable this test for js until js gets proper skipRandomNumbers. + when not defined(js): + const size = 1000 + var + rands: array[size, Rand] + randSet: HashSet[Rand] + for i in 0..<size: + rands[i] = initRand() + randSet.incl rands[i] + + doAssert randSet.len == size + + # Checks random number sequences overlapping. + const numRepeat = 100 + for i in 0..<size: + for j in 0..<numRepeat: + discard rands[i].next + doAssert rands[i] notin randSet + +block: # bug #22360 + const size = 1000 + var fc = 0 + var tc = 0 + + for _ in 1..size: + let s = rand(bool) + + if s: + inc tc + else: + inc fc + + when defined(js) and not compileOption("jsbigint64"): + doAssert (tc, fc) == (515, 485), $(tc, fc) + else: + doAssert (tc, fc) == (510, 490), $(tc, fc) + +block: + when defined(js) and not compileOption("jsbigint64"): + doAssert rand(int32.high) == 335507522 + else: + doAssert rand(int32.high) == 607539621 |