|Re: [eigen] inconsistent cwise() support|
[ Thread Index |
| More lists.tuxfamily.org/eigen Archives
- To: eigen@xxxxxxxxxxxxxxxxxxx
- Subject: Re: [eigen] inconsistent cwise() support
- From: Benoit Jacob <jacob.benoit.1@xxxxxxxxx>
- Date: Mon, 16 Nov 2009 15:40:04 -0500
- Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:content-type; bh=3yVvUt4+jAKWok56vVHzBhIYXQg9NdlWmeHiROUzacI=; b=dEkEqoYwx6RnFYVJ/KBZHHkVBDwsNZZ9zui6niU54QcSG+2/oKWP2zaDcboQWXwZ/B aE4XSz04+OZQTPDG8vR8kU3VG721Xxxn88vB7c/VdK8yEpXOSFi/CuUNk6798++6KkdT NFflwvIUyQ6zLUH4RmhhLajVyHdHwnjRvg8E0=
- Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=lbcOEfozVfxiPUxwJxvEDmrAfbyXGpuwupNBS0C/D6JrzlOc61WXwg6VcTrXhFq0IH S0RN5KCqsBvDSIKuM4jyWmi1XPGolm60m7ulH5MvBgVlSHrb9xOhy0izeIcp+ioBWKIM le2L9L7fjdvlTu9JpQ1joqGMrHK67uEFIB2tQ=
2009/11/16 Hauke Heibel <hauke.heibel@xxxxxxxxxxxxxx>:
> On Mon, Nov 16, 2009 at 7:22 PM, Benoit Jacob <jacob.benoit.1@xxxxxxxxx>
>> It seems like what you want is Gael's proposal for "true array support".
> Not really, since I am really required to work on matrices - actually I was
> working on spectral clustering involving eigenvalue decompositions (so real
> linear algebra stuff).
>> vector - scalar is not a standard operation; it doesn't have a
>> geometric meaning. Actually matrix - scalar is sometimes used as
>> matrix - scalar*Identity, so that's another reason not to let it mean
>> coeff-wise substraction.
> I totally agree, I was just thinking about consistingly supporting (I do
> even volunteer to implement it)
> .cwise() += | -= | /= | *=
oh, i see.
Yes, I agree with your proposal, it would be cool if you implement it.
It's true that there's no reason not to let .cwise syntax always work.
> and not in general
> MatrixBase::operator += etc.
> I just think that some problems (formulated in an algebraic framework) do
> sometimes need individual rescaling and sometimes even shifting when you
> need to work e.g. on zero-mean input data.
> - Hauke