I need to evaluate the following derivate:
$$\frac{dF}{d\Psi} = \frac{d}{d\Psi}\left[\beta\Delta\Psi+\alpha\left|\Psi\right|^2\Psi+\mu\Psi-i\vec{v}\cdot\bar{\nabla}\Psi\right]$$
where $\Psi$ is a complex eigenfunction $\Psi(x,y,t)$. In particular I am not sure on how to evaluate the derivate when there is also the Laplacian of Psi and the gradient. Any suggestion?
