Create random 2d array in rust

Question

How would you create a random 2d array in rust equivalent to numpy's:

np.random.rand(3, 2)

array([[0.81103811, 0.51529836],
       [0.02255365, 0.28580315],
       [0.97909856, 0.05897878]])

Answer 1

You can use ndarray-rand crate which is an integration of rand and ndarray crate.

This is the equivalent code for np.random.rand(3, 2)

use ndarray::Array;
use ndarray_rand::{rand_distr::Standard, RandomExt};

fn main() {
    println!("{:.4}", Array::<f64, _>::random((3, 2), Standard));
    // Example Output:
    //[[0.3762, 0.5176],
    // [0.0949, 0.3432],
    // [0.8329, 0.5704]]
}

• Array::<f64, _> can be changed to different types like Array::<u64, _> to get random value from u64 set.
• Uniform distribution can be used to earn flexibility to have custom range
• https://crates.io/crates/rand_distr is directly exported by ndarray-rand you can have implementation of probability distributions from here: https://docs.rs/rand_distr/latest/rand_distr/#distributions, or you can implement your custom distribution
• RadnomExt also provides functionality like sample_axis to select random axis(for numpy users*; I believe this is similar to numpy.random.Generator.choice )

Dependency

Since ndarray-rand is a Random Extension for ndarray crate you'll need ndarray crate in your project, your Cargo.toml should look like this:

[dependencies]
ndarray-rand = "*" #todo select compatible version to ndarray vice-versa
ndarray = "*" #todo ...