[petsc-users] Errors from large matrices

[Choi240]

Thank you for your fast reply. However, I was already using 64 bit pointer.

-------- Original message --------
Subject: Re: [petsc-users] Errors from large matrices 
From: Barry Smith <bsmith at mcs.anl.gov> 
To: Joon hee Choi <choi240 at purdue.edu> 
CC: petsc-users at mcs.anl.gov 


On May 26, 2013, at 6:19 AM, Joon hee Choi <choi240 at purdue.edu> wrote:

> Hello all,
> 
> I need to multiply a large seqaij matrix(X1) and a maij(or baij) matrix(CC). I set up X1 (size:4273949x108965941330383, nonzeros:143599552) and C (size:25495389x10, nonzeros:254953890) and created a maij matrix CC from C. However, I got errors such as out of memory and Caught signal number 11 SEGV: Segmentation Violation, probably memory access out of range. Is this memory problem, and do I have to change seqaij into mpiaij and use multi processors? Or do I have another methods fixing it? If you know the method, then please let me know it. Thank you.

http://www.mcs.anl.gov/petsc/documentation/faq.html#with-64-bit-indices


> 
> Joon
> 
> 
> Code:
>  ...
>  ierr = MatCreate(PETSC_COMM_SELF, &X1); CHKERRQ(ierr);
>  ierr = MatSetSizes(X1, PETSC_DECIDE, PETSC_DECIDE, I, J*K); CHKERRQ(ierr);
>  ierr = MatSetBlockSizes(X1, I, J); CHKERRQ(ierr);
>  ierr = MatSetType(X1, MATSEQAIJ); CHKERRQ(ierr);
>  ierr = MatSeqAIJSetPreallocation(X1, 0, nnz); CHKERRQ(ierr);
> 
>  for (int x=0; x<tups.size(); x++) {
>       i = std::tr1::get<0>(tups[x]);
>       j = std::tr1::get<2>(tups[x]) + std::tr1::get<1>(tups[x])*J;
>       val = std::tr1::get<3>(tups[x]);
>       ierr = MatSetValues(X1, 1, &i, 1, &j, &val, INSERT_VALUES); CHKERRQ(ierr);
>  }
>  ierr = MatAssemblyBegin(X1, MAT_FINAL_ASSEMBLY);
>  ierr = MatAssemblyEnd(X1, MAT_FINAL_ASSEMBLY);
>  ierr = PetscGetTime(&v1); CHKERRQ(ierr);
>  ierr = PetscPrintf(PETSC_COMM_WORLD, "Setup Time: %2.1e \n", v1-v); CHKERRQ(ierr);
> 
>  // Create a matrix C (K x R) with all values 1
>  ierr = MatCreateSeqAIJ(PETSC_COMM_SELF, K, R, R, NULL, &C); CHKERRQ(ierr);
>  for (k=0; k<K; k++) {
>       for (r=0; r<R; r++) {
>            ierr = MatSetValues(C, 1, &k, 1, &r, &one, INSERT_VALUES); CHKERRQ(ierr);
>       }
>  }
>  ierr = MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY); CHKERRQ(ierr);
>  ierr = MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY); CHKERRQ(ierr);
> 
>  ierr = M...
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