Function vsharp 

pub fn vsharp(
    field: &[f64],
    mask: &[u8],
    nx: usize,
    ny: usize,
    nz: usize,
    vsx: f64,
    vsy: f64,
    vsz: f64,
    radii: &[f64],
    threshold: f64,
) -> (Vec<f64>, Vec<u8>)

Returns

(local_field, eroded_mask)