Hi all,
As far as I understand, using MatSetValues for new non-zero entries will cause an error if MAT_NEW_NONZERO_LOCATION_ERR== PETSC_TRUE. Setting MAT_NEW_NONZERO_LOCATION_ERR to PETSC_FALSE is also undesirable since it will slow down the code, and in some cases, the performance loss will be extreme. However, is there any solution for a matrix that the number of non-zeros on each of its rows is fixed in both diagonal and off-diagonal parts, but the location (the column number) of the non-zero entries may vary during the procedures? I can use MAT_NEW_NONZERO_LOCATION_ERR== PETSC_TRUE, but it is important to me that the code runs as fast as possible. Any help is much appreciated. Best wishes, Ali
