Question about MatSetValues

[Sh.M]

Hi,

When I now create these binary files they also create an info file. However
the info file is empty. Is it supposed to be like this?

With best regards, Shaman Mahmoudi

----- Original Message ----- 
From: "Sh.M" <shaman.mahmoudi.7099 at student.uu.se>
To: <petsc-users at mcs.anl.gov>
Sent: Sunday, June 04, 2006 7:41 PM
Subject: Re: Question about MatSetValues


> Thanks.
>
> I will try that.
>
> With best regards, Shaman Mahmoudi
>
> ----- Original Message ----- 
> From: "Barry Smith" <bsmith at mcs.anl.gov>
> To: <petsc-users at mcs.anl.gov>
> Sent: Sunday, June 04, 2006 7:20 PM
> Subject: Re: Question about MatSetValues
>
>
> >
> >    Write a SEQUENTIAL program that reads in the matrix and then
> > saves it with MatView() to a binary file (can do a right hand side also)
> > then use ksp/ksp/examples/tutorials/ex10.c which uses MatLoad() to solve
> the
> > system.
> >
> >    See for example src/mat/examples/tests/ex32.c for an example of
> > sequential program for reading in ASCII matrix. Also ex34.c ex50.c also
> ex78.c
> >
> >
> >
> >     Barry
> >
> >
> > On Sun, 4 Jun 2006, Sh.M wrote:
> >
> > > Hi,
> > >
> > > When using the MatSetValues function with one CPU only, it will
> cache/save
> > > the values locally and then distribute them to the other processes
with
> > > MatAssemblyBegin/MatAssemblyEnd? Is this true? What happens with the
> > > cached/saved values afterwards? Are they released? Is there a way to
not
> > > cache/save the data locally at all?
> > >
> > > I am asking these questions because right now speed is not of highest
> > > priority, but memory is. And unfortunately in my case I do not
generate
> the
> > > matrix by my own and instead read it from a file obtained from "real
> world"
> > > data samples.
> > >
> > > I have read/distributed the matrix in a couple of different ways; for
> > > example CPU 0 reads the file, and then calls MatSetValues.. One other
> way
> > > has been that CPU 0 reads the file, sends the rows that belong to the
> other
> > > processes to the other processes and those processes call MatSetValues
> by
> > > their own on the received rows. And last one is that I have split the
> file
> > > into several smaller files and several processes reads their own file
> and
> > > call MatSetValues on the data they have read from their own file. To
> make it
> > > more convenient for me, the number of files have been maximum number
of
> > > processors that I have used in my simulations. So If maximum number of
> > > processors is 64, then number of files is 64. And if 8 processors are
> used,
> > > then each processor reads 8 files etc.
> > >
> > > I dont believe any of the approaches I have used are elegant...
> > >
> > > What would you guys do if you had a file in CSR format, and you want
to
> read
> > > it, distribute it and then solve it if memory usage is of highest
> priority?
> > >
> > > With best regards, Shaman Mahmoudi
> > >
> > >
> >
>