Function identity_k 

pub fn identity_k<T: Zero + One, D0: Dim, D1: Dim>(
    n: usize,
    k: isize,
) -> Array<T, (D0, D1)>

Creates a diagonal matrix of size n x n with ones on a specified diagonal.

The diagonal can be shifted using k:

• k = 0 → main diagonal (default, standard identity)
• k > 0 → k-th diagonal above the main one
• k < 0 → k-th diagonal below the main one

Examples

use mdarray::{Const, tensor};
use mdarray_linalg::utils::identity_k;

let i3 = identity_k::<f64, Const<3>, Const<3>>(3, 1);
assert_eq!(i3, tensor![[0.,1.,0.],[0.,0.,1.],[0.,0.,0.]]);