Last active
May 27, 2023 06:29
-
-
Save dacr/09ea0bd0d697c7719676bd461b6ef3c2 to your computer and use it in GitHub Desktop.
Compute PI using montecarlo approach, i.e. using a random generator. / published by https://github.com/dacr/code-examples-manager #3cbc2540-3f21-4114-8218-7e461a470bb6/2288ca863469f3be322b04658d6f7503e7a548e
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
// summary : Compute PI using montecarlo approach, i.e. using a random generator. | |
// keywords : scala, scalatest, pi, random, algorithm, montecarlo, math, tailrec, @testable | |
// publish : gist | |
// authors : David Crosson | |
// license : Apache NON-AI License Version 2.0 (https://raw.githubusercontent.com/non-ai-licenses/non-ai-licenses/main/NON-AI-APACHE2) | |
// id : 3cbc2540-3f21-4114-8218-7e461a470bb6 | |
// created-on : 2020-05-31T19:54:52Z | |
// managed-by : https://github.com/dacr/code-examples-manager | |
// run-with : scala-cli $file | |
// --------------------- | |
//> using scala "3.3.0" | |
//> using dep "org.scalatest::scalatest:3.2.16" | |
// --------------------- | |
import org.scalatest.*, flatspec.*, matchers.* | |
def monteCarloPI(iterations:Long=10000000L):Double = { | |
@annotation.tailrec | |
def worker(in:Long, out:Long, remainingIterations:Long):Double = { | |
if (remainingIterations==0) 4d*in/(in+out) | |
else { | |
val x = Math.random() | |
val y = Math.random() | |
if (x * x + y * y > 1) worker(in, out + 1, remainingIterations - 1) | |
else worker(in + 1, out, remainingIterations - 1) | |
} | |
} | |
worker(0,0,iterations) | |
} | |
object pitest extends AnyFlatSpec with should.Matchers { | |
"pi monte carlo calculus" should "return a precise enough pi value" in { | |
monteCarloPI() shouldBe 3.14158d +- 0.001d | |
} | |
} | |
pitest.execute() |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment