On Thu, Aug 21, 2008 at 9:01 AM, Boyce Griffith <griffith at courant.nyu.edu> wrote: > Hi, Folks -- > > I am using a home-grown "multi-Vec" (i.e., vector of vectors) implementation > with a PETSc nonlinear solver. I'd like to be able to use PETSc's > matrix-free Jacobian with this solver along with a PCCOMPOSITE > preconditioner; however, it seems like I need to override the default > implementation of MatGetVecs in order to get this to work. > > Is there a kosher way to do this?
You can use MatShellSetOperation() and set the operation MATOP_GET_VECS. Despite the name, that function can let you set/change the implementation of Mat operations for any matrix type. Try to make the call to MatShellSetOperation() in the Jacobian routine and let me know if you have trouble. > Thanks, > > -- Boyce > > -- Lisandro Dalc?n --------------- Centro Internacional de M?todos Computacionales en Ingenier?a (CIMEC) Instituto de Desarrollo Tecnol?gico para la Industria Qu?mica (INTEC) Consejo Nacional de Investigaciones Cient?ficas y T?cnicas (CONICET) PTLC - G?emes 3450, (3000) Santa Fe, Argentina Tel/Fax: +54-(0)342-451.1594
