"PETSc's powerful preconditioners" are constructed from knowledge about the matrix entries; if you do not provide any information about the matrix entries it cannot construct any preconditioners. You need to provide the matrix as a PETSc AIJ or BAIJ Mat in order to use those preconditioners.
Barry On Apr 14, 2009, at 1:04 PM, Yongcheng Zhou wrote: > hi there, > > I want to link my own package with PETSc in order to make use of its > various preconditioners. I am using > matrix free method, so that I can directly refer the large matrix > saved in my own format. The connection > works OK without preconditioners, but runs into trouble when most of > the preconditioners is called. > For example, I got this message when using PCICC preconditionder: > > Matrix format shell does not have a built-in PETSc direct solver! > > So my question is how to utilize PETSc's powerful preconditioners for > my matrix-free application. > > Thanks, > > Rocky
