Partial Differential Equation Toolbox

Help please, I need to solve this differential equation in Matlab (where "a" is a constant parameter, it can be taken by any), I wanted to use the Partial Differential Equation Toolbox, but I ran into a problem, the elliptic equation in this Toolbox is represented in a vector form, namely -div(c*grad(u))+a*u=f.

Please help me convert my equation to this form and tell me how it can be done or at least name the sources of information from which I can learn this knowledge.

I really need to solve this equation in Matlab,so please tell me how it can be done.

[Torsten]

What is the domain where you want to solve the equation and what are the boundary and initial conditions ?

[Dmitrij Soldatenko]

I can take any, at my discretion

Answer 1

[Torsten]

Take

c = [- x, x - y ; - ( x - y ), - y]

Then

-div(c*grad(u)) = x * d^2u/dx^2 + y * d^2u/dy^2

Section 2-62 in

http://www.cmap.polytechnique.fr/~jingrebeccali/frenchvietnammaster2_files/2017/pdetool_doc

[Dmitrij Soldatenko]

Thank you very much.

[Bosnian Kingdom]

Can you put you code here or can you send me on e-mail or private message? I really need example of pde solution.

Thanks in advance.