Dear all I am trying to solve a steady state problem using TSPSEUDO and am unclear about the preconditioner. The PDE is 3-d compressible Euler/NS equations solved with FV on unstructured grids.
I am using matrix-free approach (-snes_mf_operator) and want to provide my own matrix-free preconditioner using PCSHELL. For the problem du/dt = R(u) the update would be [I - dt*J(u)]*du = dt*R(u), J(u) = R’(u) u = u + du Does my PCSHELL have to provide a preconditioner for J or for I - dt*J ? Thanks praveen
