To extend over what Wolfgang said, the most likely causes for failure
with the Chebyshev preconditioner are:
- the vector supplying the matrix diagonal (via the field
AdditionalData::preconditioner) contains Inf or NaN entries, which in
turn result from either a ill-formed differential
Thank you Wolfgang. I didin't dive much into the Chebyshev preconditioner
because I'm not familiar with it.
I assume it's because the CG solver inside Chebyshev preconditioner didn't
converge or what.
But as you stated, if NaN should only get from NaN elements and divided by
zero, then I may
It's strange that the iteration breaks at step 0. If I try right
preconditioning, it breaks at step 1 with nan. Besides, if there is only on
multigrid level, the problem is solved correctly with 1 iteration, so matrices
should be correct. The coarse solution is good enough for smoothing.
Thank you Prof. for the information. I'll check it out.
On Fri, Feb 10, 2023 at 11:25 PM Wolfgang Bangerth
wrote:
>
> Deepika,
> GridGenerator has a number of functions that do similar things to what you
> want to do, such as plate_with_a_hole(), channel_with_hole(), specifically
> merging
On 2/11/23 04:09, Masoud Ahmadi wrote:
My goal of using this function is simply to get the DoF of some specific nodes
which I know their coordinates; so, are there any alternative options that I
won't have to use this function?
In order to determine the DoF indices for a given vertex, you
Hello everyone!
This is deal.II newsletter #241.
It automatically reports recently merged features and discussions about the
deal.II finite element library.
## Below you find a list of recently proposed or merged features:
#14793: doc: replace FE_DGRT with correct name (proposed by tjhei)
Hi,
I'm solving a multi-component problem in MatrixFree framework,
preconditioned by geometric multigrid. The code runs good for several cases
except one (with different geometry and boundary condition). The error is
"Iterative method reported convergence failure in step 0.
The
Hello,
DataOut is made to add data to a mesh. It cannot be used to do what you
want. The easiest way to do what you want is to write the vectors to a file
using print() and then do the plot using matlab or python.
Best,
Bruno
On Saturday, February 11, 2023 at 9:27:06 AM UTC-5
Dear deal.ii community,
first of all, a big thank you for all the effort going into this
software.
I am currently developing an application and I stumbled upon
implementing periodic boundary conditions for discontinuous Lagrange
elements.
I found the following thread
