Because my (class member) functions to construct A(x) and b(x) rely on the same (class member) "x" as registered with KSP. I could perhaps set up my A and b routines to take "x" as an argument, but this is a bit unnatural for a class member function, and I can not quickly predict the consequences for the rest of the code either.
Dominik On Tue, May 8, 2012 at 3:22 PM, Jed Brown <jedbrown at mcs.anl.gov> wrote: > Why a copy? > > On May 8, 2012 8:16 AM, "Dominik Szczerba" <dominik at itis.ethz.ch> wrote: >> >> >> I am currently assuming they are different and am using the "x" from >> >> the signature to set up my A(x) and b(x). I was thinking if they are >> >> the same (i.e. corresponding to x_n in the Newton method), I could >> >> significantly simplify my code. But apparently "x" in the signature is >> >> not simply x_n because of the involved line search, correct me if I am >> >> wrong. >> > >> > >> > Correct, they are not the same. How could it possibly simplify your code >> > "significantly"? >> >> Significantly was perhaps too strong a word, but a vector copy and a >> couple lines of code would certainly go. Never mind, thanks a lot for >> the clarification. >> >> Dominik
