[petsc-users] Matrix Factorization fill

[Rongliang Chen]

Hello All,

Thank you for your reply.
This result is obtained by running my own application code.

Best,
Rongliang

------------------------------
>
> Message: 5
> Date: Tue, 20 Sep 2011 19:06:41 -0500
> From: Matthew Knepley <knepley at gmail.com>
> Subject: Re: [petsc-users] Matrix Factorization fill
> To: PETSc users list <petsc-users at mcs.anl.gov>
> Message-ID:
>        <CAMYG4Gmnbt3GQdqa+sQFUetcrQqgnM_a7NwpA3SzibY7ANbYBg at mail.gmail.com
> >
> Content-Type: text/plain; charset="iso-8859-1"
>
> On Tue, Sep 20, 2011 at 7:02 PM, Rongliang Chen <rongliang.chan at gmail.com
> >wrote:
>
> > Hi,
> >
> > I have a question about the Sparse Matrix Factorization fill.
> > Following the manual, I use the option "-info" and get the following
> > result:
> >
> > [0] MatLUFactorSymbolic_SeqAIJ(): Reallocs 0 Fill ratio:given 5 needed
> > 5.0746e-05
> > [0] MatLUFactorSymbolic_SeqAIJ(): Run with -pc_factor_fill 5.0746e-05 or
> > use
> > [0] MatLUFactorSymbolic_SeqAIJ(): PCFactorSetFill(pc,5.0746e-05);
> >
> > What's the numbers mean in "Reallocs 0 Fill ratio:given 5 needed
> > 5.0746e-05"?
> > Does the " Run with -pc_factor_fill 5.0746e-05 or use" mean that I should
> > run my code with option " -pc_factor_fill 5.0746e-05"?
> >
>
> "Reallocs 0": no additional malloc()s were needed
>
> "Fill rato: give 5 needed 5.0746e-05" We guessed that the factor would need
> 5 times the matrix memory. It actually needed a lot less.
>
> If you run -pc_factor_fill 5.0746e-05, you will get the same performance
> and
> use a lot less memory.
>
>    Matt
>
>
> > But when I run my code with option "-snes_view", I get "factor fill ratio
> > given 5, needed 3.28701".
> > So what should I give to the option "-pc_factor_fill", 3.28701 or
> > 5.0746e-05? Thanks.
> >
> > Best,
> > Rongliang
> >
>
>
>
> --
> What most experimenters take for granted before they begin their
> experiments
> is infinitely more interesting than any results to which their experiments
> lead.
> -- Norbert Wiener
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> ------------------------------
>
> Message: 6
> Date: Tue, 20 Sep 2011 20:07:44 -0500
> From: Barry Smith <bsmith at mcs.anl.gov>
> Subject: Re: [petsc-users] Matrix Factorization fill
> To: PETSc users list <petsc-users at mcs.anl.gov>
> Message-ID: <48785310-F532-48E8-8220-88392A5047FA at mcs.anl.gov>
> Content-Type: text/plain; charset=us-ascii
>
>
> On Sep 20, 2011, at 7:02 PM, Rongliang Chen wrote:
>
> > Hi,
> >
> > I have a question about the Sparse Matrix Factorization fill.
> > Following the manual, I use the option "-info" and get the following
> result:
> >
> > [0] MatLUFactorSymbolic_SeqAIJ(): Reallocs 0 Fill ratio:given 5 needed
> 5.0746e-05
> > [0] MatLUFactorSymbolic_SeqAIJ(): Run with -pc_factor_fill 5.0746e-05 or
> use
> > [0] MatLUFactorSymbolic_SeqAIJ(): PCFactorSetFill(pc,5.0746e-05);
> >
> > What's the numbers mean in "Reallocs 0 Fill ratio:given 5 needed
> 5.0746e-05"?
> > Does the " Run with -pc_factor_fill 5.0746e-05 or use" mean that I should
> run my code with option " -pc_factor_fill 5.0746e-05"?
>
>   This is printed incorrectly due to a change in our data structures, we
> will fix it.
>
> >
> > But when I run my code with option "-snes_view", I get "factor fill ratio
> given 5, needed 3.28701".
> > So what should I give to the option "-pc_factor_fill", 3.28701 or
> 5.0746e-05? Thanks.
>
>   The 3.28701
>
> Barrty
>
> >
> > Best,
> > Rongliang
>
>
>
> ------------------------------
>
> Message: 7
> Date: Tue, 20 Sep 2011 22:21:53 -0500 (CDT)
> From: Shri <abhyshr at mcs.anl.gov>
> Subject: Re: [petsc-users] Matrix Factorization fill
> To: PETSc users list <petsc-users at mcs.anl.gov>
> Message-ID:
>        <1333380760.24263.1316575313230.JavaMail.root at zimbra.anl.gov>
> Content-Type: text/plain; charset=utf-8
>
> I can't reproduce this with snes/examples/tutorials/ex3.c,ex5.c, or ex19.c.
> Are you running a petsc example or your own application code?
>
> Shri
> ----- Original Message -----
> > On Sep 20, 2011, at 7:02 PM, Rongliang Chen wrote:
> >
> > > Hi,
> > >
> > > I have a question about the Sparse Matrix Factorization fill.
> > > Following the manual, I use the option "-info" and get the following
> > > result:
> > >
> > > [0] MatLUFactorSymbolic_SeqAIJ(): Reallocs 0 Fill ratio:given 5
> > > needed 5.0746e-05
> > > [0] MatLUFactorSymbolic_SeqAIJ(): Run with -pc_factor_fill
> > > 5.0746e-05 or use
> > > [0] MatLUFactorSymbolic_SeqAIJ(): PCFactorSetFill(pc,5.0746e-05);
> > >
> > > What's the numbers mean in "Reallocs 0 Fill ratio:given 5 needed
> > > 5.0746e-05"?
> > > Does the " Run with -pc_factor_fill 5.0746e-05 or use" mean that I
> > > should run my code with option " -pc_factor_fill 5.0746e-05"?
> >
> > This is printed incorrectly due to a change in our data structures, we
> > will fix it.
> >
> > >
> > > But when I run my code with option "-snes_view", I get "factor fill
> > > ratio given 5, needed 3.28701".
> > > So what should I give to the option "-pc_factor_fill", 3.28701 or
> > > 5.0746e-05? Thanks.
> >
> > The 3.28701
> >
> > Barrty
> >
> > >
> > > Best,
> > > Rongliang
>
>
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