[petsc-users] petsc viewer

[Shaohao Chen]

Dear all,

I can use VecView(vec, viewer) and correctly output a distributed vector. But when I use it in an 
iteration, it doesn't work. My codes are like: 

PetscViewerCreate(PETSC_COMM_WORLD, &viewer1);
......  // modify values of vec
VecView(vec, viewer1) ;  // correct

PetscViewerCreate(PETSC_COMM_WORLD, &viewer2);
for(i=0;i<n;i++){
  ......  // modify values of vec
  VecView(vec, viewer2) ;  // incorrect
}

In viewer1, it outputs the whole correct vector. In viewer2, it just outputs part of the vector and 
then stop at the first step of the iteration. And it becomes much slower when I add the VecView line 
in the iteration. The same happens to MatView. What is the problem here? 

Thank you for your attention!

--
Shaohao Chen
Department of Physics & Astronomy, 
Louisiana State University, 
Baton Rouge, LA