Added another rand example

This commit is contained in:
David Harris 2017-02-25 16:27:08 -06:00
parent d66b7fbf58
commit 308e35f2ba
3 changed files with 126 additions and 3 deletions

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@ -90,7 +90,12 @@ MathJax.Hub.Queue(function() {
<p><a href="https://doc.rust-lang.org/rand/rand/index.html"><img src="https://img.shields.io/crates/v/rand.svg?label=rand" alt="rand-badge" /></a></p>
<a class="header" href="#example-monte-carlo-integration" name="example-monte-carlo-integration"><h3>Example: Monte carlo integration</h3></a>
<p>Use the <code>rand</code> crate to generate random samples and approximate
$\int_{0}^{\pi} sin(x) dx$ using monte carlo method.</p>
$\int_{0}^{\pi} sin(x) dx$ using monte carlo.</p>
<p><em>Key concepts:</em></p>
<ul>
<li>Creating thread-specific RNG</li>
<li>Generating real numbers over an interval</li>
</ul>
<pre><code class="language-rust">extern crate rand;
use rand::Rng;
@ -127,6 +132,41 @@ fn main() {
println!(&quot;{}&quot;, monte_carlo(0., f32::consts::PI, 200_000));
}
</code></pre>
<a class="header" href="#example-generating-random-rgb-colors" name="example-generating-random-rgb-colors"><h3>Example: Generating random RGB colors</h3></a>
<p>A <em>trait</em> is a language feature that tells the Rust compiler about functionality a type must provide.</p>
<p>Rust has the powerful ability to create traits for your own types.
One example is <code>rand::Rand</code>. Any type that implements Rand can use the
polymorphic function <code>Rng::gen()</code> to generate random types.</p>
<p><em>Key concepts:</em></p>
<ul>
<li>Generating a random structure</li>
</ul>
<pre><code class="language-rust">extern crate rand;
use rand::Rng;
use rand::Rand;
#[derive(Debug)] // Allows us to print using {:?} format specifier
struct Color { // RGB Color struct
r: f64,
g: f64,
b: f64,
}
// Implementing Rand for type Color
impl Rand for Color {
fn rand&lt;R: Rng&gt;(rng: &amp;mut R) -&gt; Self {
Color {r: rng.next_f64(), b: rng.next_f64(), g: rng.next_f64()}
}
}
fn main() {
// Generate a random Color and print to stdout
let mut rng = rand::thread_rng();
let c: Color = rng.gen();
println!(&quot;{:?}&quot;, c);
}
</code></pre>
<!-- Links -->
</div>

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@ -144,7 +144,12 @@ MathJax.Hub.Queue(function() {
<p><a href="https://doc.rust-lang.org/rand/rand/index.html"><img src="https://img.shields.io/crates/v/rand.svg?label=rand" alt="rand-badge" /></a></p>
<a class="header" href="#example-monte-carlo-integration" name="example-monte-carlo-integration"><h3>Example: Monte carlo integration</h3></a>
<p>Use the <code>rand</code> crate to generate random samples and approximate
$\int_{0}^{\pi} sin(x) dx$ using monte carlo method.</p>
$\int_{0}^{\pi} sin(x) dx$ using monte carlo.</p>
<p><em>Key concepts:</em></p>
<ul>
<li>Creating thread-specific RNG</li>
<li>Generating real numbers over an interval</li>
</ul>
<pre><code class="language-rust">extern crate rand;
use rand::Rng;
@ -181,6 +186,41 @@ fn main() {
println!(&quot;{}&quot;, monte_carlo(0., f32::consts::PI, 200_000));
}
</code></pre>
<a class="header" href="#example-generating-random-rgb-colors" name="example-generating-random-rgb-colors"><h3>Example: Generating random RGB colors</h3></a>
<p>A <em>trait</em> is a language feature that tells the Rust compiler about functionality a type must provide.</p>
<p>Rust has the powerful ability to create traits for your own types.
One example is <code>rand::Rand</code>. Any type that implements Rand can use the
polymorphic function <code>Rng::gen()</code> to generate random types.</p>
<p><em>Key concepts:</em></p>
<ul>
<li>Generating a random structure</li>
</ul>
<pre><code class="language-rust">extern crate rand;
use rand::Rng;
use rand::Rand;
#[derive(Debug)] // Allows us to print using {:?} format specifier
struct Color { // RGB Color struct
r: f64,
g: f64,
b: f64,
}
// Implementing Rand for type Color
impl Rand for Color {
fn rand&lt;R: Rng&gt;(rng: &amp;mut R) -&gt; Self {
Color {r: rng.next_f64(), b: rng.next_f64(), g: rng.next_f64()}
}
}
fn main() {
// Generate a random Color and print to stdout
let mut rng = rand::thread_rng();
let c: Color = rng.gen();
println!(&quot;{:?}&quot;, c);
}
</code></pre>
<!-- Links -->
<a class="header" href="#byteorder" name="byteorder"><h1>Byteorder</h1></a>
<p><a href="https://docs.rs/byteorder"><img src="https://img.shields.io/crates/v/rustc-serialize.svg?label=byteorder" alt="byteorder-badge" /></a></p>

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@ -23,7 +23,11 @@ MathJax.Hub.Queue(function() {
### Example: Monte carlo integration
Use the `rand` crate to generate random samples and approximate
$\int_{0}^{\pi} sin(x) dx$ using monte carlo method.
$\int_{0}^{\pi} sin(x) dx$ using monte carlo.
*Key concepts:*
* Creating thread-specific RNG
* Generating real numbers over an interval
```rust
extern crate rand;
@ -62,6 +66,45 @@ fn main() {
}
```
### Example: Generating random RGB colors
A *trait* is a language feature that tells the Rust compiler about functionality a type must provide.
Rust has the powerful ability to create traits for your own types.
One example is `rand::Rand`. Any type that implements Rand can use the
polymorphic function `Rng::gen()` to generate random types.
*Key concepts:*
* Generating a random structure
```rust
extern crate rand;
use rand::Rng;
use rand::Rand;
#[derive(Debug)] // Allows us to print using {:?} format specifier
struct Color { // RGB Color struct
r: f64,
g: f64,
b: f64,
}
// Implementing Rand for type Color
impl Rand for Color {
fn rand<R: Rng>(rng: &mut R) -> Self {
Color {r: rng.next_f64(), b: rng.next_f64(), g: rng.next_f64()}
}
}
fn main() {
// Generate a random Color and print to stdout
let mut rng = rand::thread_rng();
let c: Color = rng.gen();
println!("{:?}", c);
}
```
<!-- Links -->
[rand-badge]: https://img.shields.io/crates/v/rand.svg?label=rand