Re: [deal.II] How to convert stiffness matrix in global degrees of freedom into stiffness matrix in global cells

2023-11-13 Thread Lance Zhang
Hello Wolfgang, thanks very much for your information. I got the point. Best regards Lance Wolfgang Bangerth 于 2023年11月13日周一 21:01写道: > > On 11/13/23 03:05, Lance Zhang wrote: > > > > I wonder whether the stiffness matrix could be converted to a matrix > > with rows = cell_numbers and

Re: [deal.II] How to convert stiffness matrix in global degrees of freedom into stiffness matrix in global cells

2023-11-13 Thread Wolfgang Bangerth
On 11/13/23 03:05, Lance Zhang wrote: I wonder whether the stiffness matrix could be converted to a matrix with rows = cell_numbers and columns = cell_numbers. Lance: I think I mentioned this before: You can't. The entries of the stiffness matrix are sums over contributions from different

Re: [deal.II] How to convert stiffness matrix in global degrees of freedom into stiffness matrix in global cells

2023-11-13 Thread Lance Zhang
Hello Wolfgang, thanks for your reply. I wonder whether the stiffness matrix could be converted to a matrix with rows = cell_numbers and columns = cell_numbers. I tried to write the gradient with rows = degree_of_freedom into with rows = cell_numbers. ### for (unsigned int i =

Re: [deal.II] How to convert stiffness matrix in global degrees of freedom into stiffness matrix in global cells

2023-10-30 Thread Wolfgang Bangerth
On 10/30/23 15:54, Lance Zhang wrote: may I know how the stiffness matrix  in global degrees of freedom could be converted into  stiffness matrix in global cells? Lance: How do you define "stiffness matrix in global cells" mathematically? Best W. -- The deal.II project is located at

[deal.II] How to convert stiffness matrix in global degrees of freedom into stiffness matrix in global cells

2023-10-30 Thread Lance Zhang
Hello team, may I know how the stiffness matrix in global degrees of freedom could be converted into stiffness matrix in global cells? I would like to use cook_memebrane.cc to get a stiffness matrix in a way of global cells. Currently,I only got the stiffness matrix