Function submatrix

crates/openquant/src/onc.rs:305–314

(m: &DMatrix<f64>, idx: &[usize])

}

fn submatrix(m: &DMatrix<f64>, idx: &[usize]) -> DMatrix<f64> {
    let n = idx.len();
    let mut out = DMatrix::zeros(n, n);
    for (i, &ri) in idx.iter().enumerate() {
        for (j, &cj) in idx.iter().enumerate() {
            out[(i, j)] = m[(ri, cj)];
        }
    }
    out
}

fn corr_to_distance(corr: &DMatrix<f64>) -> DMatrix<f64> {
    let n = corr.nrows();