Seven-sided dice from five-sided dice: Difference between revisions

=={{header|Nim}}==

We use the distribution checker from task [[Simple Random Distribution Checker#Nim|Simple Random Distribution Checker]].

<lang Nim>import random, tables

proc dice5(): int = rand(1..5)

proc dice7(): int =

while true:

let val = 5 * dice5() + dice5() - 6

if val < 21:

return val div 3 + 1

proc checkDist(f: proc(): int; repeat: Positive; tolerance: float) =

var counts: CountTable[int]

for _ in 1..repeat:

counts.inc f()

let expected = (repeat / counts.len).toInt # Rounded to nearest.

let allowedDelta = (expected.toFloat * tolerance / 100).toInt

var maxDelta = 0

for val, count in counts.pairs:

let d = abs(count - expected)

if d > maxDelta: maxDelta = d

let status = if maxDelta <= allowedDelta: "passed" else: "failed"

echo "Checking with a tolerance of ", tolerance, "%."

echo "Random generator ", status, " the uniformity test."

echo "Max delta = ", maxDelta, " Allowed delta = ", allowedDelta

when isMainModule:

import random

randomize()

checkDist(dice7, 1_000_000, 0.5)</lang>

{{out}}

<pre>Checking with a tolerance of 0.5%.

Random generator passed the uniformity test.

Max delta = 559 Allowed delta = 714</pre>