Re: [Libmesh-users] deform the mesh

Thanks, Roy! I will avoid hanging nodes definitely. Just to make sure, what you're suggesting is the following, right? for it_node n = n_nodes-distance(it_node, it_node_end); displacement(0) = (*system.solution)(3n); displacement(1) = (*system.solution)(3n+1); displacement(2) =

Re: [Libmesh-users] sparse LU or Cholesky decomposition

Hi all, Thank you all for all the helpful comments and suggestions! I will let you know how it went. Thanks again, Kathrin > Am 08.12.2016 um 14:29 schrieb Roy Stogner : > > > On Thu, 8 Dec 2016, Kathrin Smetana wrote: > >> Unfortunately my matrix has a dimension of 1M \times 1M… > > I w

Re: [Libmesh-users] linear interpolation

On Thu, 8 Dec 2016, Michael Povolotskyi wrote: > does libmesh have a tool to perform a linear interpolation of a 3D > function from one mesh to another? In code: create a MeshFunction with the source mesh+system and do project_solution on the target mesh+system. >From the command line: use $LIB

Re: [Libmesh-users] deform the mesh

On Thu, 8 Dec 2016, Xinzeng Feng wrote: > I have a problem which needs information on both initial and deformed > meshes. To be short, can someone tell me how to map a mesh or an element > according to the calculated displacement in libMesh? Thanks! Looping over nodes and adding the specified di

Re: [Libmesh-users] sparse LU or Cholesky decomposition

On Thu, 8 Dec 2016, Kathrin Smetana wrote: Unfortunately my matrix has a dimension of 1M \times 1M… I was picturing smaller... I would not try 1M dofs with a direct solver. Saving an incomplete Cholesky factorization would probably still be a big win. There's a LinearSolver::reuse_precondi

[Libmesh-users] linear interpolation

Hello, does libmesh have a tool to perform a linear interpolation of a 3D function from one mesh to another? Thank you, Michael. -- Michael Povolotskyi, PhD Research Assistant Professor Network for Computational Nanotechnology Hall for Discover and Learning Research, Room 441 207 South Martin Ji

Re: [Libmesh-users] sparse LU or Cholesky decomposition

Hi Fande, Thanks very much for your comments and suggestions! I use the solutions of the linear system later on within an eigenvalue problem. The eigenvalues of the latter seem to be very sensitive regarding the accuracy of the solutions of the linear system of equations. Thanks, Kathrin Am

Re: [Libmesh-users] sparse LU or Cholesky decomposition

On Thu, Dec 8, 2016 at 11:03 AM, Kong, Fande wrote: > On Thu, Dec 8, 2016 at 10:44 AM, Kathrin Smetana wrote: > > > Dear libmesh users/developers, > > > > I have to solve a linear system of equations (system size approximately > > 10^6) very often (about 5000 times). The linear system of equatio

Re: [Libmesh-users] sparse LU or Cholesky decomposition

On Thu, Dec 8, 2016 at 10:44 AM, Kathrin Smetana wrote: > Dear libmesh users/developers, > > I have to solve a linear system of equations (system size approximately > 10^6) very often (about 5000 times). The linear system of equations is the > result of a FEM discretization of 3D linear elasticit

Re: [Libmesh-users] sparse LU or Cholesky decomposition

On Thu, Dec 8, 2016 at 11:21 AM, Kathrin Smetana wrote: > Hi John, > > Thanks very much for your comments and suggestions! > > In the Eigen documentation they have a Sparse LU decomposition with > Umfpack and Super LU support, but I have not checked the implementation. > > Unfortunately my matrix

[Libmesh-users] deform the mesh

Hi, I have a problem which needs information on both initial and deformed meshes. To be short, can someone tell me how to map a mesh or an element according to the calculated displacement in libMesh? Thanks! Xinzeng -- Xinzeng Feng, Ph.D. Institute for Computational Engineering and Sciences, Po

Re: [Libmesh-users] sparse LU or Cholesky decomposition

Hi John, Thanks very much for your comments and suggestions! In the Eigen documentation they have a Sparse LU decomposition with Umfpack and Super LU support, but I have not checked the implementation. Unfortunately my matrix has a dimension of 1M \times 1M… Thanks, Kathrin Am 08.12.2016 um 1

Re: [Libmesh-users] sparse LU or Cholesky decomposition

Hi Roy, Thanks very much for your comments and suggestion! If I want to compute the Cholesky decomposition just once and reuse this decomposition for all subsequent solver calls, can I do that via passing a specific solver option when running the program or do I need to cast the libmesh Sparse

Re: [Libmesh-users] sparse LU or Cholesky decomposition

On Thu, Dec 8, 2016 at 10:44 AM, Kathrin Smetana wrote: > Dear libmesh users/developers, > > I have to solve a linear system of equations (system size approximately > 10^6) very often (about 5000 times). The linear system of equations is the > result of a FEM discretization of 3D linear elasticit

Re: [Libmesh-users] sparse LU or Cholesky decomposition

On Thu, 8 Dec 2016, Kathrin Smetana wrote: > I have to solve a linear system of equations (system size > approximately 10^6) very often (about 5000 times). The linear system > of equations is the result of a FEM discretization of 3D linear > elasticity. > > I thought about using a sparse Cholesky

[Libmesh-users] sparse LU or Cholesky decomposition

Dear libmesh users/developers, I have to solve a linear system of equations (system size approximately 10^6) very often (about 5000 times). The linear system of equations is the result of a FEM discretization of 3D linear elasticity. I thought about using a sparse Cholesky decomposition as the