[petsc-users] Computing part of the inverse of a large matrix

[Jan Grießer via petsc-users]

Hi all,
i am using petsc4py. I am dealing with rather large sparse matrices up to
600kx600k and i am interested in calculating a part of the inverse of the
matrix(I know it will be a dense matrix). Due to the nature of my problem,
I am only interested in approximately the first 1000 rows and 1000 columns
(i.e. a large block in the upper left ofthe matrix).  Before I start to
play around now, I wanted to ask if there is a clever way to tackle this
kind of problem in PETSc in principle. For any input I would be very
grateful!
Greetings Jan