Ah, yes, I didn't notice the difference. Now its working. Thank you!
Michael
Am 27.09.19 um 15:54 schrieb Jose E. Roman:
> I now see what is happening. In the expression of the paper the antishift has
> different sign compared to the expression used in SLEPc (see the users
> manual):
>
>
I now see what is happening. In the expression of the paper the antishift has
different sign compared to the expression used in SLEPc (see the users manual):
(A-sigma*B)^{-1}*(A+nu*B)x = \theta x
So nu=-sigma is a forbidden value, otherwise both factors cancel out (I will
fix the interface so
Yes, with sinvert its working. And using -eps_target instead of
-st_shift didn't change anything.
I also just sent you the matrices for reproduction of the issue.
Michael
Am 27.09.19 um 13:32 schrieb Jose E. Roman:
> Try setting -eps_target -1 instead of -st_shift -1
> Does sinvert work with
Try setting -eps_target -1 instead of -st_shift -1
Does sinvert work with target -1?
Can you send me the matrices so that I can reproduce the issue?
Jose
> El 27 sept 2019, a las 13:11, Michael Werner escribió:
>
> Thank you for the link to the paper, it's quite interesting and pretty
> close
Thank you for the link to the paper, it's quite interesting and pretty
close to what I'm doing. I'm currently also using the "inexact" approach
for my application, and in general it works, as long as the ksp
tolerance is low enough. However, I was hoping to speed up convergence
towards the
> El 25 sept 2019, a las 16:18, Michael Werner via petsc-users
> escribió:
>
> Hello,
>
> I'm looking for advice on how to set shift and antishift for the cayley
> spectral transformation. So far I've been using sinvert to find the
> eigenvalues with the smallest real part (but possibly
Hello,
I'm looking for advice on how to set shift and antishift for the cayley
spectral transformation. So far I've been using sinvert to find the
eigenvalues with the smallest real part (but possibly large imaginary
part). For this, I use the following options:
-st_type sinvert
-eps_target -0.05
