Thanks! That’s awesome to hear—I’d love to see how your Raku numerical integration project turns out!

You can email me if you want to, I'll be happy to help.

for ]-inf, inf[ integrals, you can use Gauss Hermite method, just keep in mind to multiply your function with exp(x^2).

    use integrate::{
        gauss_quadrature::hermite::gauss_hermite_rule,
    };
    use statrs::distribution::{Continuous, Normal};

    fn dnorm(x: f64) -> f64 {
        Normal::new(0.0, 1.0).unwrap().pdf(x)* x.powi(2).exp()
    }

    fn main() {
        let n: usize = 170;
        let result = gauss_hermite_rule(dnorm, n);
        println!("Result: {:?}", result);
    }

I got Result: 1.0000000183827922.

this was mainly to use an Iteration free method in this paper: https://www.cfm.brown.edu/faculty/gk/APMA2560/Handouts/GL_qu...

this method is much faster and simpler.