[petsc-users] Question about preallocation and getOwnership functions

[Sun, Hui]

Hello,

The following lines of code give me trouble because PETSc gives me an error 
message saying the object A is in a wrong state, and Must call 
MatXXXSetPreallocation() or MatSetUp() on argument 1 "mat" before 
MatGetOwnershipRange().

Here is part of the code:


    ierr = MatCreate(PETSC_COMM_WORLD,&A);CHKERRQ(ierr);

    ierr = 
MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,2*nx*ny,2*nx*ny);CHKERRQ(ierr);

    ierr = MatSetType(A,MATAIJ);CHKERRQ(ierr);

    ierr = MatMPIAIJSetPreallocation(A,9,NULL,9,NULL);CHKERRQ(ierr);

    ierr = MatGetOwnershipRange(A, &start, &end);CHKERRQ(ierr);


I think I have called MatMPIAIJSetPreallocation, so what might be causing the 
problem here?


Best,

Hui