Elmer Discussion Forum

HI there, i have started working on the integral constraint again and i was hoping that someone could dive into the INvPerm for me a little bit. As i understand, in the pseudo code above there are ase many rows as in the original matrix. I would like to create a constraint matrix with just one row n...

Hello everybody, i am not sure about the usage of the keyword "Linear System Symmetric =Logical True" and hoped for an explanation. SO i have a very classic heat equation that ends up in an symmetric linear system. I use the jacobi ("none") or ILU2 Preconditioner for it and solve...

HI there, i am not very experienced with cmake so i ask before i do: the online documentation says to install elmer with cmake -DWITH_ELMERGUI:BOOL=FALSE -DWITH_MPI:BOOL=FALSE -DCMAKE_INSTALL_PREFIX=../install The question is about the two FALSE in this line. If i want a GUI and want to have the mpi...

Hello, i have a follow up question to the constant bulk usage. So i think that i understand now how the constant bulk matrices are implemented in the solvers. Now my problem is that i change my timestep and as i understood the global matrix in elmer is the matrix G=1\dt*M+K where M is the mass matri...

HI there,

i am not quite sure but isnt the AT=A giving the pointer A (which is pointing to solver%matrix) into AT so that effectively AT is pointing to solver%matrix? And the stuff that you have allocated for AT is floating without a pointer?

best regards
Franz

You can definitly do this with a user subroutine. i am not sure if this is yet documented but it works like a user function but instead of having a return value you have a further argumnent in the header which is the returned tensor.

i actualy don'T know if it works with MATC

best regards

Franz

Hi there, i am once again struggling with hypre a little bit. I have a user defined solver with several dofs that are not a classical vector field but a monolithic solution of two equaitons. Now i try to use haypre to solve these. Thsat doesnt really worjk out for me. First question: when do i have ...

HI there,
i have a follow up question to this. If i wantr to evaluate something on all nodes where a solvber is active, can i use listgetreal directly?

best regards

Franz

Hello,

i found a way around this by actually using the main variable and taking the values by striding, as you have shown in your last reply,

thanks peter,

Franz

HI,

ok so i got something wrong. I was a bit sloppy in my first post. I actually have an unknown where i rename the components And i calculate UNk in the one solver and the nuse VariableGet(...,'pot 2') in another solver. Does that make a difference?