******************* This email 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 [image: {U}_n] at time n and transforms it to [image: \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 [image: {U}_{(n+1)}] will be formed using [image: \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 [image: \tilde{U}] , which are different from the [image: 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 [image: {U}_n] to [image: \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 =( _____|_|____||________| http://sci.utah.edu/people/vidhi.html