[aspect-devel] Questions about Integrating the GyPSuM Tomography Model into ASPECT

[Wolfgang Bangerth]

David,

> A few of us have been working on integrating the GyPSuM tomography model into 
> ASPECT, [...]
> In an effort to temporarily skirt this issue, [...] However, we need to know ASPECT's position in the mesh since this 
> affects our temperature perturbation calculation. I noticed that this was 
> being done in the templates by passing const Point<3> &position, so is there 
> is an equivalent way to do this in a class?
> 
> 
> Lastly, these calculations require the inner and outer radii [...]

I think you're trying to do too many things at once :-) When developing 
software, you want to do this in small increments that you can then 
independently test. For example, if you're seeing very large numbers that are 
clearly wrong in a parallel code, try to test things in a sequential setting 
first -- does it work correctly there? That is, does it *produce reasonable 
numbers*, and are these numbers *correct*?

When testing these things, it's ok to hard-code the inner and outer radius for 
a moment. You can later generalize this by reading parameters from some model 
at run-time, but first make sure that the results you get are actually correct 
before you start making the code more complicated.

So, concretely:
* Can you read in the GyPSuM files?
* When you run the code on one processor, does it run through in debug mode
   without errors?
* If it runs, do the initial temperature fields look reasonable?
* Have you verified that they are in fact correct, for example by comparing
   the numerical values with those obtained with another program? For this
   step, it's also ok to not run a time-dependent simulation -- just do one
   time step and output initial temperature and other fields via their
   respective visualization postprocessors.

If you've made it this far, you're already 3/4 there and adding some run-time 
parameters such as radii as well as parallelization will be easy. But first 
steps first -- how far down this list above can you make it?

Cheers
  W.

-- 
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Wolfgang Bangerth          email:                 bangerth at colostate.edu
                            www: http://www.math.colostate.edu/~bangerth/