Misterious BLACS

Misterious BLACS

Hello.
I use BLACS and ScaLapack to inverse dense matrix.
And I got some troubles.

I set up nprow and npcol for block-cyclic distribution for example 2, 2.
and run this routine

nprow = 2;
npcol=2;
Cblacs_get(0,0,&ictxt);
Cblacs_gridinit(&ictxt,"R",nprow,npcol);
Cblacs_gridinfo(ictxt,&nprow,&npcol,&myrow,&mycol);

The stange thing is that after Cblacs_gridinfo(..) nprow is changed as 0.
Whyis it changed?
Because it is changed to 0, numroc(..) called after that generates error.
Could you give me some ideas?
Thanks in advance.

ps. Is there another method to inverse matrix without BLACS?

2 posts / 0 new
Last post
For more complete information about compiler optimizations, see our Optimization Notice.

Quoting - phaser75
Hello.
I use BLACS and ScaLapack to inverse dense matrix.
And I got some troubles.

I set up nprow and npcol for block-cyclic distribution for example 2, 2.
and run this routine

nprow = 2;
npcol=2;
Cblacs_get(0,0,&ictxt);
Cblacs_gridinit(&ictxt,"R",nprow,npcol);
Cblacs_gridinfo(ictxt,&nprow,&npcol,&myrow,&mycol);

The stange thing is that after Cblacs_gridinfo(..) nprow is changed as 0.
Whyis it changed?
Because it is changed to 0, numroc(..) called after that generates error.
Could you give me some ideas?
Thanks in advance.

ps. Is there another method to inverse matrix without BLACS?

Hi phaser75,

I'm afraid that there are no specialists in this thread who could help you with BLACS. This thread is mainly dedicated to Intel MPI Library. You could try Lapack forum first: http://icl.cs.utk.edu/lapack-forum/

Please compare your appplication with an example here: http://www.netlib.org/lapack-dev/old/examples/test_pdgesvd.c.html

Best wishes,
Dmitry

Login to leave a comment.