[Getfem-users] Re-assemble one brick in a model

[Magnus Paulsson]

I’m using the python interface to solve a Helmholtz problem and want to repeat the solution for many different values of the Dirichlet boundary conditions. 

The question is: Can I use the model framework and only re-assemble the part that I want to change without assembling the full problem?

(Or do I have to assemble the parts myself ...) 

As I do it today I repeat the following where the “mfWF” variable is updated and assembles the full problem for each value of the boundary conditions:

################################################

    import numpy as N

    md = GF.Model('complex')

    # Helmholtz brick

    md.add_fem_variable('psi', mf) 

    md.add_initialized_fem_data('sqrtpot', mf, N.sqrt(-mfPot.astype(N.complex))) 

    md.add_Helmholtz_brick(mim,'psi','sqrtpot')

    

    # Zero boundary

    md.add_initialized_data('zerov', 0) 

    md.add_Dirichlet_condition_with_multipliers(mim,'psi',mf,[zeroSide],'zerov')

    # Wavefunction boundary

    md.add_initialized_fem_data('WF', mf, mfWF) 

    md.add_Dirichlet_condition_with_multipliers(mim, 'psi', mf, [wfSide], 'WF')

    # Periodic boundary conditions

    numPBC = pbcMat.size()[0]

    md.add_variable('mult', numPBC) 

    md.add_constraint_with_multipliers('psi', 'mult', pbcMat, N.zeros(numPBC,N.complex))

    md.solve()

################################################

What I would like to do is to replace the md.solve() line with:

    for ii in mfWFs:

        md.add_initialized_fem_data('WF', mf, ii) 

        md.solve()

Is this possible (from the documentation I kind of guess that the enable_bricks, disable_bricks etc are there for this kind of purpose but it’s not clear).

Finally, thank you for the GetFEM software. Awesome.  

-----------------------------------------------
Magnus Paulsson
Associate Professor

Dept. of Physics and Electrical Engineering
Linnaeus University
Phone: +46-480-446308
Mobile: +46-70-6942987