1 <!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Randomly sample exactly `amount` distinct indices from `0..length`, and return them in an arbitrary order (there is no guarantee of shuffling or ordering). The weights are to be provided by the input function `weights`, which will be called once for each index."><title>sample_weighted in bdk_chain::bitcoin::secp256k1::rand::seq::index - Rust</title><script>if(window.location.protocol!=="file:")document.head.insertAdjacentHTML("beforeend","SourceSerif4-Regular-6b053e98.ttf.woff2,FiraSans-Regular-0fe48ade.woff2,FiraSans-Medium-e1aa3f0a.woff2,SourceCodePro-Regular-8badfe75.ttf.woff2,SourceCodePro-Semibold-aa29a496.ttf.woff2".split(",").map(f=>`<link rel="preload" as="font" type="font/woff2" crossorigin href="../../../../../../static.files/${f}">`).join(""))</script><link rel="stylesheet" href="../../../../../../static.files/normalize-9960930a.css"><link rel="stylesheet" href="../../../../../../static.files/rustdoc-46132b98.css"><meta name="rustdoc-vars" data-root-path="../../../../../../" data-static-root-path="../../../../../../static.files/" data-current-crate="bdk_chain" data-themes="" data-resource-suffix="" data-rustdoc-version="1.85.0-nightly (a4cb3c831 2024-12-17)" data-channel="nightly" data-search-js="search-036cda7a.js" data-settings-js="settings-0f613d39.js" ><script src="../../../../../../static.files/storage-59e33391.js"></script><script defer src="sidebar-items.js"></script><script defer src="../../../../../../static.files/main-5f194d8c.js"></script><noscript><link rel="stylesheet" href="../../../../../../static.files/noscript-893ab5e7.css"></noscript><link rel="alternate icon" type="image/png" href="../../../../../../static.files/favicon-32x32-6580c154.png"><link rel="icon" type="image/svg+xml" href="../../../../../../static.files/favicon-044be391.svg"></head><body class="rustdoc fn"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="mobile-topbar"><button class="sidebar-menu-toggle" title="show sidebar"></button><a class="logo-container" href="../../../../../../bdk_chain/index.html"><img src="https://github.com/bitcoindevkit/bdk/raw/master/static/bdk.png" alt=""></a></nav><nav class="sidebar"><div class="sidebar-crate"><a class="logo-container" href="../../../../../../bdk_chain/index.html"><img src="https://github.com/bitcoindevkit/bdk/raw/master/static/bdk.png" alt="logo"></a><h2><a href="../../../../../../bdk_chain/index.html">bdk_<wbr>chain</a><span class="version">0.21.0</span></h2></div><div class="sidebar-elems"><div id="rustdoc-modnav"><h2><a href="index.html">In bdk_<wbr>chain::<wbr>bitcoin::<wbr>secp256k1::<wbr>rand::<wbr>seq::<wbr>index</a></h2></div></div></nav><div class="sidebar-resizer"></div><main><div class="width-limiter"><rustdoc-search></rustdoc-search><section id="main-content" class="content"><div class="main-heading"><span class="rustdoc-breadcrumbs"><a href="../../../../../index.html">bdk_chain</a>::<wbr><a href="../../../../index.html">bitcoin</a>::<wbr><a href="../../../index.html">secp256k1</a>::<wbr><a href="../../index.html">rand</a>::<wbr><a href="../index.html">seq</a>::<wbr><a href="index.html">index</a></span><h1>Function <span class="fn">sample_weighted</span><button id="copy-path" title="Copy item path to clipboard">Copy item path</button></h1><rustdoc-toolbar></rustdoc-toolbar><span class="sub-heading"><a class="src" href="https://rust-random.github.io/rand/src/rand/seq/index.rs.html#277-283">Source</a> </span></div><pre class="rust item-decl"><code>pub fn sample_weighted<R, F, X>(
2 rng: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&mut R</a>,
3 length: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.usize.html">usize</a>,
5 amount: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.usize.html">usize</a>,
6 ) -> <a class="enum" href="https://doc.rust-lang.org/nightly/core/result/enum.Result.html" title="enum core::result::Result">Result</a><<a class="enum" href="enum.IndexVec.html" title="enum bdk_chain::bitcoin::secp256k1::rand::seq::index::IndexVec">IndexVec</a>, <a class="enum" href="../../distributions/enum.WeightedError.html" title="enum bdk_chain::bitcoin::secp256k1::rand::distributions::WeightedError">WeightedError</a>><div class="where">where
7 R: <a class="trait" href="../../trait.Rng.html" title="trait bdk_chain::bitcoin::secp256k1::rand::Rng">Rng</a> + ?<a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>,
8 F: <a class="trait" href="https://doc.rust-lang.org/nightly/core/ops/function/trait.Fn.html" title="trait core::ops::function::Fn">Fn</a>(<a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.usize.html">usize</a>) -> X,
9 X: <a class="trait" href="https://doc.rust-lang.org/nightly/core/convert/trait.Into.html" title="trait core::convert::Into">Into</a><<a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.f64.html">f64</a>>,</div></code></pre><details class="toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>Randomly sample exactly <code>amount</code> distinct indices from <code>0..length</code>, and
10 return them in an arbitrary order (there is no guarantee of shuffling or
11 ordering). The weights are to be provided by the input function <code>weights</code>,
12 which will be called once for each index.</p>
13 <p>This method is used internally by the slice sampling methods, but it can
14 sometimes be useful to have the indices themselves so this is provided as
16 <p>This implementation uses <code>O(length + amount)</code> space and <code>O(length)</code> time
17 if the “nightly” feature is enabled, or <code>O(length)</code> space and
18 <code>O(length + amount * log length)</code> time otherwise.</p>
19 <p>Panics if <code>amount > length</code>.</p>
20 </div></details></section></div></main></body></html>
projects / bitcoindevkit.org / blob