[petsc-users] Question about PETSC

Hello! My name is Valentin Egorov. I am from Russia. And I have a question for you about PETSC. I would like to make a programm on Fortran with PETSC, but I can't. I have a matrix 400*400. I have also vector B with 400 elements. I need to solve linear equations. Could you help me to do it. I can't

Re: [petsc-users] How to determine a reasonable relative tolerance to iteratively solve a linear system of equations?

> For a small linear system, I usually use 1e-6, or 1e-8, or 1e-10, etc. But > for a very large linear system, do I need to use a relative tolerance much > smaller than the previous I use? (Theoretically I think the relative > tolerance has nothing related to system size). > I agree with the

Re: [petsc-users] How to determine a reasonable relative tolerance to iteratively solve a linear system of equations?

On Tue, Mar 14, 2017 at 5:42 PM, Barry Smith wrote: > > > On Mar 14, 2017, at 5:32 PM, Fangbo Wang wrote: > > > > Hi, > > > > I know this is not a problem specific to PETSc, but I have this doubt > for a long time and want to ask the experts here. > > >