create a function that performs matrix multiplication in rust

To perform matrix multiplication in Rust, we can create a function that takes two matrices as arguments and returns their product. Here is an example implementation using Rust arrays:

main.rs
fn matrix_multiply(a: [[f64; 3]; 3], b: [[f64; 3]; 3]) -> [[f64; 3]; 3] {
    let mut result = [[0.0; 3]; 3];

    for i in 0..3 {
        for j in 0..3 {
            for k in 0..3 {
                result[i][j] += a[i][k] * b[k][j];
            }
        }
    }

    result
}
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In this example, we define a function matrix_multiply that takes two 3x3 arrays of type f64 as arguments. The function returns a 3x3 array containing the product of the two input matrices.

We initialize a new 3x3 matrix result with all zeros. We then use three nested loops to iterate over the elements of result, calculating each element as the sum of the products of the corresponding elements of the two input matrices.

To use this function, simply call it with two input matrices and assign the result to a new matrix:

main.rs
let a = [[1.0, 2.0, 3.0], [4.0, 5.0, 6.0], [7.0, 8.0, 9.0]];
let b = [[9.0, 8.0, 7.0], [6.0, 5.0, 4.0], [3.0, 2.0, 1.0]];

let result = matrix_multiply(a, b);

println!("Result: {:?}", result);
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This will output the product of a and b:

main.rs
Result: [[30.0, 24.0, 18.0], [84.0, 69.0, 54.0], [138.0, 114.0, 90.0]]
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