Initial commit, Added example of stratified sampling

.gitignore

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+/target

Cargo.lock

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+# It is not intended for manual editing.
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+ "libc",
+ "wasi",
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Cargo.toml

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+[package]
+name = "raytracing-the-rest-of-your-life"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+rand = "0.8.4"

src/main.rs

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+use rand::Rng;
+
+fn main() {
+    let mut inside_circle = 0u64;
+    let mut inside_circle_stratified = 0u64;
+    let mut rng = rand::thread_rng();
+
+    const SQRT_N: u64 = 10000;
+
+    for i in 0..SQRT_N {
+        for j in 0..SQRT_N {
+            let mut x: f64 = rng.gen_range(-1.0..=1.0);
+            let mut y: f64 = rng.gen_range(-1.0..=1.0);
+
+            if x * x + y * y < 1.0 {
+                inside_circle += 1;
+            }
+
+            x = (2.0f64 * (i as f64 + rng.gen::<f64>()) / SQRT_N as f64) - 1.0;
+            y = (2.0f64 * (j as f64 + rng.gen::<f64>()) / SQRT_N as f64) - 1.0;
+
+            if x * x + y * y < 1.0 {
+                inside_circle_stratified += 1;
+            }
+        }
+    }
+
+    let n = SQRT_N as f64 * SQRT_N as f64;
+
+    println!(
+        "regular estimation = {} stratified estimate = {}",
+        4.0 * inside_circle as f64 / n,
+        4.0 * inside_circle_stratified as f64 / n
+    );
+}