Difference between u.split() and split(u)
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 ------------------------------------------------------
On 4 Nov 2015, at 14:51, Buesing, Henrik <HBuesing@eonerc.rwth-aachen.de> wrote:
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…
It is an ongoing issue that we would like to resolve! Rule of thumb: Use: split(u) if you're going to use the split things in UFL forms Use: u.split() if you want to be able to do point wise operations on the split fields, or output them. These two things result in different types of objects (but wrapping the same, underlying, coefficients). Lawrence
participants (2)
-
Buesing, Henrik
-
Lawrence Mitchell