Re: [eigen] combine matrix blocks

[Stefan Ulbrich <s.ulbrich@xxxxxxxxxxxxxx>]

thanks for the answer. Actually, block / corner and minor don't allow  
you to select the for example the columns 1,3,4,6. The closest thing I  
found in Eigen is the Minor Class which allows to omit one row/col. I  
now tried to clone and to modificate this class but haven't finished  
it yet (still problems with io.h). This class will take two row- 
vectors that serve as a proxy for the addressing of the coefficients  
(allows for permutations, repetition of elements...). What do you  
think: do I have to worry about speed using this method? Does the use  
of Minor result in lower speed?
In the same way I want to create a class that connects matrix with the  
same amount of rows (cols) to a single one.
cheers,
stefan

Am 02.07.2009 um 19:46nachm. schrieb Thomas Capricelli:

> Erm, all of this seems already available,have you read the tutorial
> http://eigen.tuxfamily.org/dox/TutorialCore.html
>
> especially the part
> http://eigen.tuxfamily.org/dox/TutorialCore.html#TutorialCoreMatrixBlocks
>
> Anything specific you think about that can not currently be done ?
>
> regards,
> Thomas
>
> In data giovedì 02 luglio 2009 18:47:16, Stefan Ulbrich ha scritto:
> : > Hello,
> > in matlab you can select a partial matrix by explicitly specifying
> > which cols and rows to take from the original matrix, e.g. with
> > A([1,3],[2 4])
> > further, it would be interesting to combine blocks into a matrix that
> > serves as a proxy to the elements: A = [B C]
> > I'd really would really like to see that functionality in eigen2. Do
> > you think this is possible? Do you have any suggestions on how to
> > start implementing it?
> >
> > best regards,
> > Stefan
>
> --
> Thomas Capricelli <orzel@xxxxxxxxxxxxxxx>
> http://www.freehackers.org/thomas