MATLAB: PDE toolbox c coefficient

Partial Differential Equation Toolboxpde toolbox

*Hi I have two PDE equations and I want to solve them using Matlab PDE and I don't know how to find C because it is very confusing. The equations are as follows.
(∂^2 ψ)/(∂^2 x)=(∂Q_x)/∂x
(∂^2 ψ)/(∂^2 y)=(∂Q_y)/∂y*

Best Answer

Your equations are not a form that fits into PDE Toolbox framework.
In fact, they seem strange to me in any case. The first equation can be integrated to give
(∂ ψ)/(∂ x)=(Q_x) + K, where K is a constant of integration
Similarly,
(∂ ψ)/(∂ y)=(Q_y) + K2.
So it seems that you can find ψ by integrating Q_x or Q_y. However, it seems that this integration will likely lead to inconsistencies, unless Q_x and Q_y have very particular forms. Imagine integrating over x first then y, or y first then x. You might arrive at two different values for ψ.
Alan Weiss
MATLAB mathematical toolbox documentation