[ET Trac] [Einstein Toolkit] #2173: Test "Poisson equation" example

[Einstein Toolkit]

#2173: Test "Poisson equation" example
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  Reporter:  Roland Haas              |      Owner:  Roland Haas
      Type:  task                     |     Status:  review
  Priority:  major                    |  Milestone:  ET_2018_08
 Component:  EinsteinToolkit website  |    Version:  development version
Resolution:                           |   Keywords:
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Comment (by Roland Haas):

 In the call on 2018-0802 a suggestion was made to mabye re-instantiate the
 5 Gaussians. param.ccl right now claims that 20 gaussians are supported,
 so supporting 5 is not actually fixing the "bug" but instead only making
 the gallery example work.

 I new pull request enabling 20 gaussians is here:

 I have quickly checked on runtime and find that run time of the generated
 routine is:

 ||= number of Gaussians =||= run time (s) =||= total run time (s) =||
 || 2                     || 139            || 287                  ||
 || 5                     || 305            || 582                  ||
 || 20                    || 869            || 1030                 ||

 So basically the CT_Analytic function's runtime is scaling almost linearly
 with the number of Gaussians. Note that this is a version of the
 poisson.par file where the max. number of iterations in the ML scheme has
 been reduced to 2 from 200 so presumably in a real run of the parfile
 `CT_Analytic` would not take >50% of the runtime since it only runs once
 and not once per grid sweep.

 I will thus prepare and test a commit allowing up to 5 Gaussians which
 lets one run the gallery example as shown.

 Only relative numbers matter as the absolute numbers would change with
 processor speed etc.

-- 
Ticket URL: <https://trac.einsteintoolkit.org/ticket/2173#comment:5>
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