forked from Mirror/wren
f3493d0499
* Optimize Random.sample(_, _) for performance * Make tests treat random samples as unordered * Test all sample sizes possible * Tweak random sampling algorithm for performance
28 lines
799 B
Plaintext
28 lines
799 B
Plaintext
import "random" for Random
|
|
|
|
var random = Random.new(12345)
|
|
|
|
// Should choose all elements with roughly equal probability.
|
|
var list = (0...10).toList
|
|
var binom = [1, 10, 45, 120, 210, 252, 210, 120, 45, 10, 1]
|
|
|
|
for (k in 0..10) {
|
|
var count = binom[k]
|
|
|
|
var histogram = {}
|
|
for (i in 1..count * 100) {
|
|
var sample = random.sample(list, k)
|
|
// Create a bitmask to represent the unordered set.
|
|
var bitmask = 0
|
|
sample.each {|s| bitmask = bitmask | (1 << s) }
|
|
if (!histogram.containsKey(bitmask)) histogram[bitmask] = 0
|
|
histogram[bitmask] = histogram[bitmask] + 1
|
|
}
|
|
|
|
if (histogram.count != count) System.print("!!! %(count) %(histogram.count)")
|
|
for (key in histogram.keys) {
|
|
var error = (histogram[key] - 100).abs
|
|
if (error > 50) System.print("!!! %(error)")
|
|
}
|
|
}
|