[Libmesh-users] Saving calculated quantity

[<an...@tn...>]

John

John Peterson writes:
 > Martin L=FCthi writes:
 >  > Is there an easy way to output calculated quantities to the GMV outp=
 > ut
 >  > files? I want to calculate e.g. stresses (or some other quantitiy
 >  > which is not a system variable), and hav it appear in the output fil=
 > e.
 > You might add it as a "dummy" system variable which is just
 > computed via a post-processing step.  Then it could be written
 > out as normal to gmv.

Thanks for the answer. There is a problem with this. If I add the
variable the beginning, the system gives a null solution (because the
variable is not used in the element loop). Adding it after just before
the write command results in some runtime error messages.

I was thinking about using an additional vector with
system.add_vector.

Best, Martin