Dear all, I want to construct a matrix by blocs, each block having different sizes and partially stored by multiple processors. If I am not mistaken, the right way to do so is by using the MATNEST type. However, the following code
Call MatCreateConstantDiagonal(PETSC_COMM_WORLD,PETSC_DECIDE,PETSC_DECIDE,4,4,2.0E0_wp,A,ierr) Call MatCreateConstantDiagonal(PETSC_COMM_WORLD,PETSC_DECIDE,PETSC_DECIDE,4,4,1.0E0_wp,B,ierr) Call MatCreateNest(PETSC_COMM_WORLD,2,PETSC_NULL_INTEGER,2,PETSC_NULL_INTEGER,(/A,PETSC_NULL_MAT,PETSC_NULL_MAT,B/),C,ierr) does not generate the same matrix depending on the number of processors. It seems that it starts by everything owned by the first proc for A and B, then goes on to the second proc and so on (I hope I am being clear). Is it possible to change that ? Note that I am coding in fortran if that has ay consequence. Thank you, Sincerely, -- Clément BERGER ENS de Lyon
