Vamos a discretizar las ecuaciones que comentamos en este post. Para ello, discretizaremos las derivadas de la siguiente manera: $latex partial_x u = frac{u_{i+1,j,k}-u_{i-1,j,k}}{2h_x}$, $latex partial_y u = frac{u_{i,j+1,k}-u_{i,j-1,k}}{2h_y}$, $latex partial_z u = frac{u_{i,j,k+1}-u_{i,j,k-1}}{2h_z}$, $latex partial_{xx} u = frac{u_{i-1,j,k}-2u_{i,j,k}+u_{i+1,j,k}}{h_x^2}$, $latex partial_{yy} u = frac{u_{i,j-1,k}-2u_{i,j,k}+u_{i,j+1,k}}{h_y^2}$, $latex partial_{zz} u = frac{u_{i,j,k-1}-2u_{i,j,k}+u_{i,j,k+1}}{h_z^2}$, $latex partial_{xy} u = frac{u_{i-1,j-1,k}-u_{i+1,j-1,k}-u_{i-1,j+1,k}+u_{i+1,j+1,k}}{4h_xh_y}$, $latex …