Hi,
i had a question regarding PCSetOperators(...):
1) what is the difference between PCSetOperators and KSPSetOperators since the
description and the arguments for both functions are the same (i.e.):
"Sets the matrix associated with the linear system and a (possibly)
different
one associated with the preconditioner"
Right now, what i do to set my preconditioner is to call:
PCSetType(m_pc, PCJACOBI);
2) Is this sufficient or do i need to call PCSetOperators?
3) Do PCSetType and PCSetOperators have the same function?
Right now what i basically do to set up my solver context is to call the
following functions (in this order):
- KSPCreate //create my context
- KSPSetOperators //associate my matrix with the context
- KSPSetType //set my solver type
- PCSetType
- KSPSetUp
It seems to work, but i don't know if it is efficient and preferred way (if
there is such a thing)?
Also, do several successive solves on the same linear system with the same
preconditioner. So i pass SAME_NONZEROPATTERN as the MatStructure flag to the
KSPSetOperators call. So do i need to call PCSetOperators and pass it the
flag as well to reuse the preconditioner?
thanks for all the help
mat
