[petsc-users] Matrix Factorization fill

Hong Zhang hzhang at mcs.anl.gov
Wed Sep 21 10:32:40 CDT 2011


Rongliang:
Which petsc version do you use? Please switch to the latest release petsc-3.2.

Hong

> 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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