But you might have mallocs with the new nonzero structure. Its proably more efficient to destroy/create a new mat with the new structure.
Satish On Thu, 14 Mar 2013, Sanjay Govindjee wrote: > Found my answer, use > > call MatSetOption(Kmat,MAT_NEW_NONZERO_LOCATIONS,PETSC_TRUE,ierr) > > after the MatAssemblyEnd( ). > > > On 3/14/13 11:28 AM, Sanjay Govindjee wrote: > > Is there a mechanism for resetting a matrix's non-zero pattern? > > > > In particular, I have a preallocated a matrix, set the values, and > > assembled it. > > And used it to solve a problem. > > > > Now I would like to zero it, and reassemble it with a different non-zero > > pattern. > > Note the matrix has been preallocated so that it can accommodate both > > non-zero > > patterns. > > > > -sanjay > >
