Questions tagged [scalapack]

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row and column based distributed LU factorization

The LU parallel computation theories I've seen are based on $M\times N$ mesh computations, is there a theory for one dimensional device mesh LU parallel decomposition? For example, $A$ is a matrix. we ...
Haitao Xiao's user avatar
2 votes
1 answer
96 views

Solve linear system for only part of the solution vector

I am using the ScaLAPACK PDGESV routine to solve large dense linear systems distributed over many supercomputer nodes, but ultimately I only need a small portion of the solution vector (e.g. the first ...
quixedjetr's user avatar
2 votes
0 answers
61 views

Losing memory on each call to scalapack solve function

I am solving a large system of equations using scalapack. Some systems that should run with no problem failed, apparently due to lack of memory in an mpi call. After investigating with ...
mp_def's user avatar
  • 21
0 votes
1 answer
167 views

How to efficiently transpose distributed matrix in Scalapack?

I have a distributed matrix in block cyclic layout. Is there an efficient way to out/in place transpose a distributed matrix with scalapack? Context: I am trying to diagonalize the transpose of a ...
Aditya Kurrodu's user avatar
1 vote
1 answer
155 views

How to debug segmentation faults in large problems?

I am sorry if this question seems like off topic or opinion based, but I was not sure how to go about it. I am currently working on a 100k x 100k positive definite linear system and trying to solve it ...
ipcamit's user avatar
  • 135
10 votes
2 answers
281 views

Benchmark problems for eigenvalue reordering algorithms sought

Every real matrix $A$ can be reduce to real Schur form $T = U^T A U$ using an orthogonal similiary transform $U$. Here the matrix $T$ is quasi-triangular form with 1 by 1 or 2 by 2 blocks on the main ...
Carl Christian's user avatar
1 vote
0 answers
282 views

Kronecker product of matrices

I have to use Kronecker product of a matrix with a unit matrix is there any routine in ScaLapack or Lapack which can do so efficiently.
Puneet Sharma's user avatar
1 vote
0 answers
157 views

Computing only the $k$ biggest eigenvalues and eigenvectors with Scalapack

Given that there are eigensolvers in Scalapack that use a divide and conquer method, is there any way we can use Scalapack functions to only compute the first $k$ dominant eigenvalues and ...
Yacine E.Faris's user avatar
1 vote
1 answer
280 views

Total Flop count for LAPACK DPOSV

I am looking at the LAPACK DPOSV routine that computes the solution to the real system of linear equations A * X = B. The routine description can be found here: http://www.math.utah.edu/software/...
Mark's user avatar
  • 21
5 votes
0 answers
228 views

BLACS context value and multiple MPI communicators [closed]

I am reposting here a question previously asked in stackoverflow: as suggested in a reply to my question, scicomp could be a better place to obtain some useful comments/suggestions for my problem. I ...
Christopher23's user avatar
5 votes
2 answers
383 views

How gracefully does scalapack/pblas revert to lapack/blas in serial

If I use scalapack and pblas, and the code is run in serial (1x1 blacs process grid), how well does scalapack and pblas revert to the performance of lapack/blas? I am particularly interested in the ...
Max Hutchinson's user avatar
2 votes
1 answer
204 views

*GEMR2D documentation (scalapack)

Where can I find documentation for the P*GEMR2D routines in Fortran? I've found: Scalapack UG Undocumented related source Unanswered forum post
Max Hutchinson's user avatar