Dear all, I have a multi-physics problem and u is my unknown. I was wondering what the difference between u.split() and split(u) is. It seems that the Jacobian is only right, when I use split(u) and then further use this in subroutines. If I use u.split() my Jacobian is zero... Thank you! Henrik -- Dipl.-Math. Henrik Büsing Institute for Applied Geophysics and Geothermal Energy E.ON Energy Research Center RWTH Aachen University ------------------------------------------------------ Mathieustr. 10 | Tel +49 (0)241 80 49907 52074 Aachen, Germany | Fax +49 (0)241 80 49889 ------------------------------------------------------ http://www.eonerc.rwth-aachen.de/GGE hbuesing@eonerc.rwth-aachen.de ------------------------------------------------------