From fd091b04316db9dc5fafadbd6bdbe60b127408a9 Mon Sep 17 00:00:00 2001 From: Daniel Mueller Date: Thu, 2 Jan 2020 08:32:06 -0800 Subject: Update nitrokey crate to 0.4.0 This change finally updates the version of the nitrokey crate that we consume to 0.4.0. Along with that we update rand_core, one of its dependencies, to 0.5.1. Further more we add cfg-if in version 0.1.10 and getrandom in version 0.1.13, both of which are now new (non-development) dependencies. Import subrepo nitrokey/:nitrokey at e81057037e9b4f370b64c0a030a725bc6bdfb870 Import subrepo cfg-if/:cfg-if at 4484a6faf816ff8058088ad857b0c6bb2f4b02b2 Import subrepo getrandom/:getrandom at d661aa7e1b8cc80b47dabe3d2135b3b47d2858af Import subrepo rand/:rand at d877ed528248b52d947e0484364a4e1ae59ca502 --- rand/rand_distr/src/unit_ball.rs | 69 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 69 insertions(+) create mode 100644 rand/rand_distr/src/unit_ball.rs (limited to 'rand/rand_distr/src/unit_ball.rs') diff --git a/rand/rand_distr/src/unit_ball.rs b/rand/rand_distr/src/unit_ball.rs new file mode 100644 index 0000000..9d61627 --- /dev/null +++ b/rand/rand_distr/src/unit_ball.rs @@ -0,0 +1,69 @@ +// Copyright 2019 Developers of the Rand project. +// +// 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. + +use rand::Rng; +use crate::{Distribution, Uniform, uniform::SampleUniform}; +use crate::utils::Float; + +/// Samples uniformly from the unit ball (surface and interior) in three +/// dimensions. +/// +/// Implemented via rejection sampling. +/// +/// +/// # Example +/// +/// ``` +/// use rand_distr::{UnitBall, Distribution}; +/// +/// let v: [f64; 3] = UnitBall.sample(&mut rand::thread_rng()); +/// println!("{:?} is from the unit ball.", v) +/// ``` +#[derive(Clone, Copy, Debug)] +pub struct UnitBall; + +impl Distribution<[N; 3]> for UnitBall { + #[inline] + fn sample(&self, rng: &mut R) -> [N; 3] { + let uniform = Uniform::new(N::from(-1.), N::from(1.)); + let mut x1; + let mut x2; + let mut x3; + loop { + x1 = uniform.sample(rng); + x2 = uniform.sample(rng); + x3 = uniform.sample(rng); + if x1*x1 + x2*x2 + x3*x3 <= N::from(1.) { + break; + } + } + [x1, x2, x3] + } +} + +#[cfg(test)] +mod tests { + use crate::Distribution; + use super::UnitBall; + + #[test] + fn value_stability() { + let mut rng = crate::test::rng(2); + let expected = [ + [0.018035709265959987, -0.4348771383120438, -0.07982762085055706], + [0.10588569388223945, -0.4734350111375454, -0.7392104908825501], + [0.11060237642041049, -0.16065642822852677, -0.8444043930440075] + ]; + let samples: [[f64; 3]; 3] = [ + UnitBall.sample(&mut rng), + UnitBall.sample(&mut rng), + UnitBall.sample(&mut rng), + ]; + assert_eq!(samples, expected); + } +} -- cgit v1.2.1