From 698f8c2f01ea549d77d7dc3338a12e04c11057b9 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 17 Apr 2024 14:02:58 +0200 Subject: Adding upstream version 1.64.0+dfsg1. Signed-off-by: Daniel Baumann --- vendor/rand-0.7.3/examples/monte-carlo.rs | 51 +++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) create mode 100644 vendor/rand-0.7.3/examples/monte-carlo.rs (limited to 'vendor/rand-0.7.3/examples/monte-carlo.rs') diff --git a/vendor/rand-0.7.3/examples/monte-carlo.rs b/vendor/rand-0.7.3/examples/monte-carlo.rs new file mode 100644 index 000000000..70560d0fa --- /dev/null +++ b/vendor/rand-0.7.3/examples/monte-carlo.rs @@ -0,0 +1,51 @@ +// Copyright 2018 Developers of the Rand project. +// Copyright 2013-2018 The Rust Project Developers. +// +// Licensed under the Apache License, Version 2.0 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +//! # Monte Carlo estimation of π +//! +//! Imagine that we have a square with sides of length 2 and a unit circle +//! (radius = 1), both centered at the origin. The areas are: +//! +//! ```text +//! area of circle = πr² = π * r * r = π +//! area of square = 2² = 4 +//! ``` +//! +//! The circle is entirely within the square, so if we sample many points +//! randomly from the square, roughly π / 4 of them should be inside the circle. +//! +//! We can use the above fact to estimate the value of π: pick many points in +//! the square at random, calculate the fraction that fall within the circle, +//! and multiply this fraction by 4. + +#![cfg(feature = "std")] + +use rand::distributions::{Distribution, Uniform}; + +fn main() { + let range = Uniform::new(-1.0f64, 1.0); + let mut rng = rand::thread_rng(); + + let total = 1_000_000; + let mut in_circle = 0; + + for _ in 0..total { + let a = range.sample(&mut rng); + let b = range.sample(&mut rng); + if a * a + b * b <= 1.0 { + in_circle += 1; + } + } + + // prints something close to 3.14159... + println!( + "π is approximately {}", + 4. * (in_circle as f64) / (total as f64) + ); +} -- cgit v1.2.3