[petsc-users] BiCGStab and right preconditioning

[Kathrin Burckhardt]

Dear all,

I have a problem using BiCGStab with right preconditioning.

Solving my system using gmres everything looks ok:

   0 KSP preconditioned resid norm 4.490868831255e-04 true resid norm  
4.490868831255e-04 ||Ae||/||Ax|| 6.402973612108e-01
   1 KSP preconditioned resid norm 2.641616638766e-04 true resid norm  
2.641616638766e-04 ||Ae||/||Ax|| 3.766353965541e-01


Solving it with bcgs, however, I got:

  0 KSP preconditioned resid norm 4.490868831255e-04 true resid norm  
1.222737120188e+01 ||Ae||/||Ax|| 1.743349407273e+04
   1 KSP preconditioned resid norm 1.801799542022e-04 true resid norm  
1.222736696074e+01 ||Ae||/||Ax|| 1.743348802582e+04

What could be wrong?

Looking forward to your help,
Kathrin