You must install petsc-dev
http://www.mcs.anl.gov/petsc/petsc-as/developers/index.html to develop this new
code.
The CG implementation has detailed information about what needs to be
provided for a new Krylov method. Start by making a new directory
src/ksp/ksp/impls/lsmr and copy over to it the files
src/ksp/ksp/impls/cg/ makefile cg.c cgimpl.h call them lsmr.c and
lsmrimpl.h modify the copied over makefile to list the lsmr stuff instead of
the cg
In lsmrimpl.h put in the data structure you'll need to store all the vectors
and other information needed by lsmr in lsmr.c go through the current code and
change it all for the lsmr algorithm. You do not need to recompile all of PETSc
to access the new solver, just run make in that new directory.
You will also need to edit src/ksp/ksp/interface/itregis.c to register your
new method.
Join petsc-dev
http://www.mcs.anl.gov/petsc/petsc-as/miscellaneous/mailing-lists.html to
correspond with the petsc developers if questions/issues come up.
Have fun,
Barry
On Apr 1, 2011, at 6:02 PM, Gaurish Telang wrote:
> Hi,
>
> I am planning to implement the LSMR algorithm in PETSc which does least
> squares and is supposed to have more favourable mathematical properties than
> LSQR which has already been implemented in PETSc.
>
> But I am not really sure how to go about this, since the implementations of
> the standard KSP methods themselves look quite complicated. The manual does
> not seeem to say much
> about how to go about adding routines to the PETSc library.
>
> Could you give me guidelines I should follow while implementing a KSP method?
>
> Also is it necessary to build the PETSc library again after implementing this
> routine. If so is it necessary to make any changes to makefiles ?
>
> Regards
