Function setup_b 

pub fn setup_b<const NV: usize>(v: &VecN<NV>, wv: &VecN<NV>) -> VecN<NV>
where
    Const<NV>: DimName,
    DefaultAllocator: Allocator<Const<NV>>,

Build the unregularised right-hand side b = Wv · v.