PML boundary condition #210
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To incorporate PML abc we should probably have a list of `damp` func.
For now I get error:
`ValueError('Default `damp(x, y)` is incompatible with other args as `x_size=65`, while `x_size=200` is expected. Perhaps you forgot to override `damp(x, y)`?')`
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I'm still struggling with this error. |
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You need to make sure that JUDI.jl/src/pysource/models.py Line 260 in 83752f1 Contains your pml field or it will use the ones from EmptyModel which is a tiny model only used to create the operator |
`abc_type` may be either `damp` or `pml`. This option defines the boundary condition. `pml` kernel equations not yet implemented. It only prepares now `pmlx0,pmlx1,pmly0...` `Model` member vars. Thogh the function `pml_op` should be checked carefully if it is implemented correctly
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@mloubout I ve added I'm not sure whether I correctly implemented Model.pml_op() method. I have some troubles with implementing |
Both `nb` and `abc_type` are defined in `DiscreteGrid` structure
Done, |
What's the main blocker? |
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@mloubout basically I think it is better if I push my efforts with mistakes and then we discuss it. I will do that soon (I need few days). But ultimately I can't understand the following: for acoustic media PML abc are defined using these three equations: And further I don't know yet what are PML equations for scalar/Q-factor/VTI/TTI models. |
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yes it would return a list of three equations instead of one |
For `pml` abc it needs to add few more equations with `phi` var
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@mloubout hi, From the Devito PML example I have to implement In Devito example they are defined as follows: phi1 = TimeFunction(name="phi1",grid=grid,time_order=2,space_order=2,staggered=(x,z),dtype=np.float64)
phi2 = TimeFunction(name="phi2",grid=grid,time_order=2,space_order=2,staggered=(x,z),dtype=np.float64)but as I see we don't set any values to them even if in the Devito examples it is written about these vars: "auxiliary variables, which will be non zero only in the absorption region" Am I missing something or I can simply define them as |
Yes this is expected, these are just extra state variables for the PML region, similar to the wavefield 'u |
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@mloubout some new obstacles appeared... I define phi as Model attributes: self.phi1 = TimeFunction(name="phi1",grid=self.grid,time_order=2,space_order=2,staggered=self.grid.dimensions)
self.phi2 = TimeFunction(name="phi2",grid=self.grid,time_order=2,space_order=2,staggered=self.grid.dimensions)I have a feeling that I have to add them to Operator so they were compiled. If so what should be the right hand side? After that I will have to compute something like |
Not sure what you mean, these are just objects, the operator just generates the code for the equations you define with it https://nbviewer.org/github/devitocodes/devito/tree/master/examples/seismic/abc_methods/ For some example of oimplementation |
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I tried this today. It works well for implementing damping boundary conditions. Thank you all. |
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What I did here is:
And yet to implement in That was pretty difficult for me so I stopped this PR for the now. |
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Current implementation of damping boundary condition requires greately extending the computational area.
I hope PML do that better.
To incorporate PML abc we should probably have a list of
dampfunc.As a first step I'm trying to leave current implementation of
damp_opfunction but makeModel.dampmember as list.With that I currently get error:
ValueError('Defaultdamp(x, y)is incompatible with other args asx_size=65, whilex_size=200is expected. Perhaps you forgot to overridedamp(x, y)?')The example of PML in Devito
Appreciate any help