ishan/raytracing-the-rest-of-your-life
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testing pdfs

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This commit is contained in:
Ishan Jain 2023-05-31 10:57:29 +05:30
parent 9bdd657018
commit 3e53256e53
Signed by: ishan
GPG Key ID: 0506DB2A1CC75C27
1 changed files with 11 additions and 26 deletions
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37
src/main.rs
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@ -1,35 +1,20 @@
use rand::Rng;
#[inline]
fn pdf(x: f64) -> f64 {
3.0 * x * x / 8.0
}
fn main() {
let mut inside_circle = 0u64;
let mut inside_circle_stratified = 0u64;
let mut rng = rand::thread_rng();
const N: u64 = 100000;
let mut sum = 0.0;
const SQRT_N: u64 = 10000;
for _ in 0..N {
let x: f64 = rng.gen_range(0.0f64..=8.0).powf(1.0 / 3.0);
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;
sum += x * x / pdf(x);
}
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
);
println!("answer = {}", sum / N as f64);
}