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/weibull.rs | 86 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 86 insertions(+) create mode 100644 rand/rand_distr/src/weibull.rs (limited to 'rand/rand_distr/src/weibull.rs') diff --git a/rand/rand_distr/src/weibull.rs b/rand/rand_distr/src/weibull.rs new file mode 100644 index 0000000..ddde380 --- /dev/null +++ b/rand/rand_distr/src/weibull.rs @@ -0,0 +1,86 @@ +// Copyright 2018 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. + +//! The Weibull distribution. + +use rand::Rng; +use crate::{Distribution, OpenClosed01}; +use crate::utils::Float; + +/// Samples floating-point numbers according to the Weibull distribution +/// +/// # Example +/// ``` +/// use rand::prelude::*; +/// use rand_distr::Weibull; +/// +/// let val: f64 = thread_rng().sample(Weibull::new(1., 10.).unwrap()); +/// println!("{}", val); +/// ``` +#[derive(Clone, Copy, Debug)] +pub struct Weibull { + inv_shape: N, + scale: N, +} + +/// Error type returned from `Weibull::new`. +#[derive(Clone, Copy, Debug, PartialEq, Eq)] +pub enum Error { + /// `scale <= 0` or `nan`. + ScaleTooSmall, + /// `shape <= 0` or `nan`. + ShapeTooSmall, +} + +impl Weibull +where OpenClosed01: Distribution +{ + /// Construct a new `Weibull` distribution with given `scale` and `shape`. + pub fn new(scale: N, shape: N) -> Result, Error> { + if !(scale > N::from(0.0)) { + return Err(Error::ScaleTooSmall); + } + if !(shape > N::from(0.0)) { + return Err(Error::ShapeTooSmall); + } + Ok(Weibull { inv_shape: N::from(1.)/shape, scale }) + } +} + +impl Distribution for Weibull +where OpenClosed01: Distribution +{ + fn sample(&self, rng: &mut R) -> N { + let x: N = rng.sample(OpenClosed01); + self.scale * (-x.ln()).powf(self.inv_shape) + } +} + +#[cfg(test)] +mod tests { + use crate::Distribution; + use super::Weibull; + + #[test] + #[should_panic] + fn invalid() { + Weibull::new(0., 0.).unwrap(); + } + + #[test] + fn sample() { + let scale = 1.0; + let shape = 2.0; + let d = Weibull::new(scale, shape).unwrap(); + let mut rng = crate::test::rng(1); + for _ in 0..1000 { + let r = d.sample(&mut rng); + assert!(r >= 0.); + } + } +} -- cgit v1.2.1