A preconditioner is held in the precdata psb_prec_type data structure reported in
figure 5. The psb_prec_type
data type may contain a simple preconditioning matrix with the
associated communication descriptor.The values contained in
the iprcparm and rprcparm define tha type of
preconditioner along with all the parameters related to it; thus,
iprcparm and rprcparm define how the other records have
to be interpreted. This data structure is the basis of more complex
preconditioning strategies, which are the subject of further
research.
