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!

   ,-~~-.___._.
  / |  '     \    | |--------. 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