[petsc-users] GAMG and linear elasticity

[Tabrez Ali]

I am using solid elements and here's what I get for the smallest problem 
with -pc_type svd -pc_svd_monitor

     SVD: condition number 4.184203727999e+13, 0 of 2187 singular values 
are (nearly) zero
     SVD: smallest singular values: 9.975131304660e-01 
9.979349868120e-01 9.986761984005e-01 9.993267254639e-01 9.996135846381e-01
     SVD: largest singular values : 3.933977100529e+13 
3.933977100529e+13 4.162059658259e+13 4.162059658259e+13 4.173798159224e+13

Tabrez

On 08/31/2013 03:06 PM, Umut Tabak wrote:
> On 08/31/2013 06:25 PM, Tabrez Ali wrote:
>> Hello
>>
>> So I used PCSetCoordinates and now GAMG seems to work really well in 
>> that the number of iterations are relatively constant. Here are the 
>> number of iterations on 4 cores
>>
>> DOF       ASM    GAMG
>> 2187       15     22
>> 14739      26     22
>> 107811     51     29
>
> Hi,
>
> Just curious, what is the approximate condition number of this matrix, 
> is that modelled with domain elements like solids or thin elements 
> like shells?
>
> Best,
> U.