| Re: [eigen] Does c++ use of "norm" bother anyone else? |
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- To: eigen@xxxxxxxxxxxxxxxxxxx
- Subject: Re: [eigen] Does c++ use of "norm" bother anyone else?
- From: Benoit Jacob <jacob.benoit.1@xxxxxxxxx>
- Date: Wed, 17 Jun 2009 23:16:16 +0200
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Yes, the word "norm" is not normalized across mathematics...
Personnally I just stay away from using the word "norm" in relation to
complex numbers, instead I say "absolute value" and "squared absolute
value". So in Eigen we do abs and abs2.
So in Eigen::Complex, one may or may not implement norm() for
compatibility with std::complex, i don't have a strong opinion, but
what we must have for sure is abs and abs2.
Benoit
2009/6/17 Mark Borgerding <mark@xxxxxxxxxxxxxx>
>
> According to matlab/octave and http://en.wikipedia.org/wiki/Norm_(mathematics)
> norm(3+4j) = abs(3+4j) == 5
>
> but in C++:
> norm( complex<float>(3,4) ) == 25
> abs( complex<float>(3,4) ) == 5
>
>
> Just thought I'd mention it while we are thinking about problems to solve with Eigen::Complex.
>
>
> -- Mark
>
>
>