[petsc-users] [petsc-dev] MatCreateDense

[Jose David Bermeol]

For instance I have a matrix of 400x8 and I want to split it in two mpi process, one with the first 100 rows and the second one with the next 300 rows.

----- Original Message -----
From: "Jose David Bermeol" <jbermeol at purdue.edu>
To: "Matthew Knepley" <knepley at gmail.com>
Cc: "petsc-users" <petsc-users at mcs.anl.gov>, "petsc-dev" <petsc-dev at mcs.anl.gov>
Sent: Thursday, October 31, 2013 9:38:43 PM
Subject: Re: [petsc-dev] MatCreateDense

What do you mean with number of local columns??

Thanks

----- Original Message -----
From: "Matthew Knepley" <knepley at gmail.com>
To: "Jose David Bermeol" <jbermeol at purdue.edu>
Cc: "petsc-dev" <petsc-dev at mcs.anl.gov>, "petsc-users" <petsc-users at mcs.anl.gov>
Sent: Thursday, October 31, 2013 2:37:43 PM
Subject: Re: [petsc-dev] MatCreateDense


On Thu, Oct 31, 2013 at 1:21 PM, Jose David Bermeol < jbermeol at purdue.edu > wrote: 




Hi small question. In the method MatCreateSeqDense(MPI_Comm comm,PetscInt m,PetscInt n,PetscScalar *data,Mat *A) I'm giving the local number of rows and columns, so I should pass the total number of local columns or I should pass columns/number_of_MPI process. 



If its sequential, you pass the total number of columns. If its MatCreateMPIDense(), pass the number of local columns. This 
is used to create a vector with the same layout as y = A^T x. 


Matt 


Thanks 




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What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. 
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