Dear Jed, Thanks for your help many times. These numbers mean the total number of elements to be added using MatSetValues(). For example, at process 0, 148767+5821 elements are added to matrix B. In other words, the length of arrays (i.e. mat_b_i_partitioned, mat_b_j_partitioned and mat_b_val_partitioned) is 148767+5821. I used "ADD_VALUES" but "INSERT_VALUES" should be the same for my work.
As you suggested, I explicitly passed the number of local rows to MatSetSizes as shown below. The number of local rows agrees with a range of continuous row indices stored at array mat_b_i_partitioned. I also explicitly set up the number of local column=the matrix size. In this case, I get error message: "Sum of local lengths 156315 does not equal global length 52105, my local length 52105". I used 3 processes. I guess that number 156315 seems to be related with 3*size of my global column size. In my problem, the matrix is partitioned by rows but not by columns. In this case, how can I specify the local column size in MatSetSizes()? Evan // CODE MatCreate(PETSC_COMM_WORLD,&B); MatSetSizes(B, partitioned_row_size, ngedges_internal, ngedges_internal, ngedges_internal); MatSetType(B,MATSBAIJ); MatMPISBAIJSetPreallocation(B,1,0,d_nnz,0,o_nnz); MatSetValues(B, nentries_mat_b_partitioned, mat_b_i_partitioned, nentries_mat_b_partitioned, mat_b_j_partitioned, mat_b_val_partitioned, ADD_VALUES); MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY); MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY); //ERROR: [0]PETSC ERROR: --------------------- Error Message -------------------------------------------------------------- [0]PETSC ERROR: Nonconforming object sizes [0]PETSC ERROR: Sum of local lengths 156315 does not equal global length 52105, my local length 52105 likely a call to VecSetSizes() or MatSetSizes() is wrong. On Thu, Nov 6, 2014 at 12:23 PM, Jed Brown <[email protected]> wrote: > Evan Um <[email protected]> writes: > > > Dear PETSC users, > > > > I hope that I can have a comment about errors I got during sparse > symmetric > > matrix construction. In this example, I used three processes. The size > of a > > test matrix is 52105-by-52105. The length of array d_nnz and o_nnz is > 17461 > > at rank 0, 17111 at rank 1 and 17535 at rank 2. The two arrays exactly > > describe nnz of the diagonal and off-diagonal part. At rank 0, I tried > > to add 148767 element for the diagonal part and 5821 for the off-diagonal > > part. At rank 1, I tried to add 135826 and 19541 for the diagonal and > > off-diagonal parts, respectively. > > Do these numbers mean that the sum of all the entries in the the arrays > are 148767, 135826, etc? > > > At rank 2, I tried to add 138155 and 0 for the diagonal and > > off-diagonal parts. Rank 0 has matrix rows from 0 to 17460; rank 1 > > from 17460 to 34570 and rank 2 from 34570 to 52104. During the run, I > > got an error message: nnz cannot be greater than block row length: > > local row 17124 value 38762560 rowlength 17368. My d_nnz and o_nnz > > arrays never have a value such as 38762560. > > Use MatGetOwnershipRange() and/or pass the local sizes to MatSetSizes. > Your arrays are the wrong length, which is why the error refers to local > row 17124 or rank 1 (which is larger than the array length of 17111). > Valgrind would have told you this. >
