How to implement ∇g • ∇Ψi /|∇Ψi | and div (∇Ψi/ |∇Ψi |) terms ?

let Ψi be any matrix. gradient of Ψi i.e. ∇Ψi will give us [Ψix,Ψiy]. magnitude of Ψi i.e. /|∇Ψi| is given by mag = sqrt((Ψix.*Ψix)+(Ψiy.*Ψiy)). then [Ψix,Ψiy]./mag gives error

" Error using ./ Matrix dimensions must agree "

So I don't understand how to implement it?

Same let g be any matrix, then how to implement first term?