Dear Petsc users, I found an ancient thread discussing this problem.
https://lists.mcs.anl.gov/pipermail/petsc-users/2011-October/010607.html However, when I add call KSPSetType(ksp,KSPGMRES,ierr);CHKERRQ(ierr) call PetscOptionsSetValue(PETSC_NULL_OPTIONS,'-ksp_gmres_modifiedgramschmidt','1',ierr);CHKERRQ(ierr) the program will tell me WARNING! There are options you set that were not used! WARNING! could be spelling mistake, etc! There is one unused database option. It is: Option left: name:-ksp_gmres_modifiedgramschmidt value: 1 I would like to know the most correct way to activate the modified Gram-Schmidt orthogonalization process in Fortran. Thank you very much! Best regards. -- Zhuo Chen Department of Physics University of Alberta Edmonton Alberta, Canada T6G 2E1 http://www.pas.rochester.edu/~zchen25/
