Hi Vidhi, Just checking on old emails. Did you get any response on this question? The closest thing I can think of that might help is in the Sub stepping scheme of the IncNavierStokesSOlver. If you look at SubSteppingExtrapolate.cpp you will see there is an m_intScheme->GetSolutionVector and m_intScheme->SetSolutionVector which allows you to get access to the integration variables in physical space and update them. I do not however recall if you have access to the m_intScheme member in the Filter. Possibly it does hold the EquationSystem which may allow you to access this. Cheers, Spencer. On 16 Jun 2021, at 11:20, Vidhi Zala <vidhi.zala@utah.edu<mailto:vidhi.zala@utah.edu>> wrote: This email from vidhi.zala@utah.edu<mailto:vidhi.zala@utah.edu> originates from outside Imperial. Do not click on links and attachments unless you recognise the sender. If you trust the sender, add them to your safe senders list<https://spam.ic.ac.uk/SpamConsole/Senders.aspx> to disable email stamping for this address. Hi, I am implementing an algorithm that takes an intermediate solution [{U}_n] at time n and transforms it to [\tilde{U}_n] . Inside SolverUtils/UnsteadySystem.cpp, I want to feed this transformed value back to the TimeIntegrate() call at the beginning of the time loop, so [{U}_{(n+1)}] will be formed using [\tilde{U}_n] . I wrote a Nektar++ filter that takes the m_fields object and modifies its phys and coeffs attributes using my filter's update() method. Upon return, I verify that m_fields indeed have [\tilde{U}] , which are different from the [U] . But the change is not passed to the next integration timestep. I tried to update the local variable "fields" used to initialize the integration scheme from [{U}_n] to [\tilde{U}_n] . The integration object is still unaware of the change to the intermediate solution. I suspect that the time integration object does not expose a setter method for the solution vector objects. I checked all the existing Nektar++ filters, but from my understanding, none of those change the values of the intermediate solutions. The only way I could get my filter to work is by calling the initializer of the time integration scheme at every timestep with the modified "fields" object. While it works for my experiments, I need advice about where architecture-wise, should I put my filter such that I don't need to modify UnsteadySystem.cpp at all. Thanks much! V -- ,-~~-.___._. / | ' \ | |--------. Vidhi Zala ( ) 0 | | | School of Computing \_/-, ,----' | | | Scientific Computing and Imaging Institute ==== !_!-v---v--. University of Utah / \-'~; .--------. / __/~| ._-""|| | vidhi.zala@utah.edu<mailto:vidhi.zala@utah.edu> =( _____|_|____||________| http://sci.utah.edu/people/vidhi.html _______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk<mailto:Nektar-users@imperial.ac.uk> https://mailman.ic.ac.uk/mailman/listinfo/nektar-users