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- To: eigen@xxxxxxxxxxxxxxxxxxx
- Subject: Re: [eigen] documentation: the long tutorial
- From: Benoit Jacob <jacob.benoit.1@xxxxxxxxx>
- Date: Mon, 21 Jun 2010 07:22:38 -0400
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2010/6/21 Carlos Becker <carlosbecker@xxxxxxxxx>:
> Thanks for the feedback. When you talk about declaring an object as an Array
> rather than a Matrix, which would be the advantages?
It's not a matter of advantages or inconvenients. Array and Matrix
stand on an equal footing, they just do different things.
- Matrix supports linear algebraic operations.
- Array supports general array operations.
> Is there any penalty
> for using matrix.array()?
No, it is cost-less (provided that compiler optimizations are
enabled). The same applies to all our expression construction, e.g.
calling matrix.block(...) or matrix.transpose() is also cost-less.
Benoit
> Sorry I am asking about this, I am not sure since
> I have never used this explicitly.
> Carlos
>
>
> On Mon, Jun 21, 2010 at 6:58 AM, Hauke Heibel <hauke.heibel@xxxxxxxxxxxxxx>
> wrote:
>>
>> Great and thank you for your effort.
>>
>> Only a few minor comments:
>>
>> - please try to use MatrixXf::Index in your examples like the
>> minCoeff() code (we just changed that recently)
>>
>> - I would add "... and indices ..." to "Maximum coefficient ... in a
>> matrix" since there exists another method taking no parameters which
>> returns the coefficients only
>>
>> - for the Array docs I would also mention the special typedefs we have
>> for Arrays like e.g. ArrayXXf
>>
>> This is a bit more important since it resembles a little inconsistency
>> which we need to point out because ArrayXXf is the MatrixXf equivalent
>> (note the two 'X' vs. one for matrices). Also, sometimes it really
>> makes sense to declare your objects right away as Arrays without using
>> the Matrix::array() method.
>>
>> Ok, that's it for the moment. If I have more time I can look more careful.
>>
>> Thanks again,
>> Hauke
>>
>> On Sun, Jun 20, 2010 at 11:45 PM, Carlos Becker <carlosbecker@xxxxxxxxx>
>> wrote:
>> > Some new stuff:
>> >
>> > Arithmetic
>> > ops: http://carlosbecker.com.ar/eigen/doc/TutorialMatrixArithmetic.html
>> > Array
>> > class: http://carlosbecker.com.ar/eigen/doc/TutorialArrayClass.html
>> >
>> > The Array class part is quite incomplete I guess. I am wondering whether
>> > more details should be added or if this is enough. I think that the
>> > examples
>> > found in http://eigen.tuxfamily.org/dox/TutorialCore.html are quite
>> > useful,
>> > does anyone know in which .dox file they are found?
>> > All feedback welcome.
>> > Carlos
>>
>>
>
>