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https://issues.apache.org/jira/browse/MATH-621?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13085074#comment-13085074
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Dr. Dietmar Wolz commented on MATH-621:
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{quote}
I see that you hard-coded the offset in most places instead of using
"INDEX_OFFSET". I still think that this place-holder would be useful to keep
track of places where the index variables might have been set to fit with the
Fortran 1-based counting... Don't you?
I am not convinced yet. I thought INDEX_OFFSET as a tool to support the
conversion. If you don't use
INDEX_OFFSET in the for loops (for int i = INDEX_OFFSET ...) I don't see why to
introduce it artificially
in other places. The final aim should be to get rid of the
Fortran-Arrays/Matrices and have 0-based access. I don't see
it essential to maintain INDEX_OFFSET as a kind of back reference to the old
Fortran code in the future.
We have the unit tests as regression test.
Just try to convert one method - lets say prelim - the way you want to have it.
The working 0-based version 0.4 should make this easy. Then lets have a look at
it.
I suspect it to become rather ugly using INDEX_OFFSET in all places. But then we
also should convert the for loops as (for int i = INDEX_OFFSET ...) so that
the code runs
again with INDEX_OFFSET=1. If you then really think it is better this way, I
will help to
convert the other methods.
> BOBYQA is missing in optimization
> ---------------------------------
>
> Key: MATH-621
> URL: https://issues.apache.org/jira/browse/MATH-621
> Project: Commons Math
> Issue Type: New Feature
> Affects Versions: 3.0
> Reporter: Dr. Dietmar Wolz
> Fix For: 3.0
>
> Attachments: BOBYQA.math.patch, BOBYQA.v02.math.patch,
> BOBYQAOptimizer0.4.zip, bobyqa.zip, bobyqa_convert.pl,
> bobyqaoptimizer0.4.zip, bobyqav0.3.zip
>
> Original Estimate: 8h
> Remaining Estimate: 8h
>
> During experiments with space flight trajectory optimizations I recently
> observed, that the direct optimization algorithm BOBYQA
> http://plato.asu.edu/ftp/other_software/bobyqa.zip
> from Mike Powell is significantly better than the simple Powell algorithm
> already in commons.math. It uses significantly lower function calls and is
> more reliable for high dimensional problems. You can replace CMA-ES in many
> more application cases by BOBYQA than by the simple Powell optimizer.
> I would like to contribute a Java port of the algorithm.
> I maintained the structure of the original FORTRAN code, so the
> code is fast but not very nice.
> License status: Michael Powell has sent the agreement via snail mail
> - it hasn't arrived yet.
> Progress: The attached patch relative to the trunk contains both the
> optimizer and the related unit tests - which are all green now.
> Performance:
> Performance difference (number of function evaluations)
> PowellOptimizer / BOBYQA for different test functions (taken from
> the unit test of BOBYQA, dimension=13 for most of the
> tests.
> Rosen = 9350 / 1283
> MinusElli = 118 / 59
> Elli = 223 / 58
> ElliRotated = 8626 / 1379
> Cigar = 353 / 60
> TwoAxes = 223 / 66
> CigTab = 362 / 60
> Sphere = 223 / 58
> Tablet = 223 / 58
> DiffPow = 421 / 928
> SsDiffPow = 614 / 219
> Ackley = 757 / 97
> Rastrigin = 340 / 64
> The number for DiffPow should be dicussed with Michael Powell,
> I will send him the details.
> Open Problems:
> Some checkstyle violations because of the original Fortran source:
> - Original method comments were copied - doesn't follow javadoc standard
> - Multiple variable declarations in one line as in the original source
> - Problems related to "goto" conversions:
> "gotos" not convertible in loops were transated into a finite automata
> (switch statement)
> "no default in switch"
> "fall through from previos case in switch"
> which usually are bad style make no sense here.
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