I have a phenomenon in matlab that is based on:
$y\,z(\Delta u/\Delta x)(x,y,z)-(x+z)(\Delta u/\Delta y)(x,y,z)+x\,y(\Delta u/\Delta z)(x,y,z)=0;\; (x,y,z) \in \mathbb R^3$.
I have $M\in\mathbb R$ the critical point domain.
Using Matlab I need to find $M$ and graphically represent $M$,into the vicinity of the point $(0,0,0)$.