[petsc-users] PetscInt overflow

[Jan Grießer]

Hi all,
i am using slepc4py and petsc4py to solve for the smallest real eigenvalues
and eigenvectors. For my test cases with a matrix A of the size 30k x 30k
solving for the smallest soutions works quite well, but when i increase the
dimension of my system to around A = 768000 x 768000 or 3 million x 3
million and ask for the smallest real 3000 (the number is increasing with
increasing system size) eigenvalues and eigenvectors i get the output (for
the 768000):
 The product 4001 times 768000 overflows the size of PetscInt; consider
reducing the number of columns, or use BVVECS instead
i understand that the requested number of eigenvectors and eigenvalues is
causing an overflow but i do not understand the solution of the problem
which is stated in the error message. Can someone tell me what exactly
BVVECS is and how i can use it? Or is there any other solution to my
problem ?
Thank you very much in advance,
Jan
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