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- To: eigen@xxxxxxxxxxxxxxxxxxx
- Subject: Re: [eigen] , basic usageSparse vectors
- From: "Gael Guennebaud" <gael.guennebaud@xxxxxxxxx>
- Date: Wed, 14 Jan 2009 23:50:16 +0100
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well, if you just want to store/read sparse data in a random order,
then std::map (or Google's dense_hash_map) are better suited.
More specifically, SparseArray is an internal class used for the
storage of SpasreVector and SparseMatrix. SpasreVector (and
SparseArray) are not designed for random read/write accesses.
Moreover, SparseVector is not designed for dynamic resize, it really
aims to represent a math vector. Eventually, if in your case you fill
the vector once, and then loop over the elements in a sequential order
(using SparseVector::Iterator), then SparseVector is just perfect !
Cheers,
Gael.
On Wed, Jan 14, 2009 at 11:27 PM, Jose Alcalá Correa <gskbyte@xxxxxxxxx> wrote:
> Hi!
>
> I'm using Eigen 2 for a little project at the University. I need to use
> dynamic sparse vectors, but I won't do matrix operations over it, just basic
> element readings and accessings. Which is the most appropiate class for
> that, SparseArray or SparseVector?
>
> Thank you very much, especially for your great work!
>
> --
> Jose Alcalá Correa
> Correo: gskbyte@xxxxxxxxx
> Mésenller: gskbyte@xxxxxxxxxxx
> http://www.gskbyte.net/
>