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https://issues.apache.org/jira/browse/MATH-667?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13114707#comment-13114707
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Phil Steitz commented on MATH-667:
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IIUC the examples and what is being proposed here, I suspect Octave is similar
to C99X (preserve signed infinities, "recover" infinities from NaNs), not
"BasicComplex." It would be instructive to compare Octave directly against the
spec or to look at the source to see if they are just delegating to the gcc
impls, which IIRC attempt to implement the spec. "BasicComplex" could be
implemented fairly easily by just removing code from what is now in trunk.
Patches welcome!
> Representations of the complex numbers
> --------------------------------------
>
> Key: MATH-667
> URL: https://issues.apache.org/jira/browse/MATH-667
> Project: Commons Math
> Issue Type: Wish
> Reporter: Gilles
> Priority: Minor
> Labels: features
> Fix For: 3.1
>
>
> Several issues have been raised about the current behaviour of the "Complex"
> class, located in package "o.a.c.m.complex" (e.g. MATH-657, MATH-620).
> The ensuing discussion revealed various, sometimes incompatible, requirements
> with focus on efficiency or consistency or backwards compatibility or
> comparison with other math packages (Octave) or faithfulness to standards
> (C99x).
> It is thus proposed to create several classes, each with a clearly defined
> purpose.
> The consensus seems to be that the first task is to implement a new
> "BasicComplex" class where the computational formulae (for computing real and
> imaginary part of a complex) will be applied directly without worrying about
> limiting cases (NaNs and infinities). Doing so will automatically produce a
> behaviour similar to the Java {{double}} primitive. It is also assumed that
> it will be the most efficient implementation for "normal" use (i.e. not
> involving limiting cases).
> This task would consist in copying most of the code in the existing "Complex"
> class over to "BasicComplex". And similarly with "ComplexTest". Then, in
> "BasicComplex", one would remove all variables that refer to NaNs and
> infinities together with checks and special assignments, and adapt the unit
> tests along the way.
> A new "ExtendedComplex" class would inherit from "BasicComplex". This class
> would aim at representing the compactified space of the complex numbers (one
> point-at-infinity).
> A new "C99Complex" class would inherit from "BasicComplex". This class would
> aim at implementing the C99x standard.
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