Function ismv_qsmjl 

fn ismv_qsmjl(
    field: &[f64],
    mask: &[u8],
    grid: &Grid,
    radius: f64,
    tol: f64,
    max_iter: Option<usize>,
    progress: impl FnMut(usize, usize),
) -> (Vec<f64>, Vec<u8>)

QSM.jl’s ismv with an explicit radius (mm); see the module docs.