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Subject: Re: [ublas] disabling the matrix expressions form sparse matrices
From: Nasos Iliopoulos (nasos_i_at_[hidden])
Date: 2012-03-11 11:43:28


I think that avoiding tho derive from matrix_container is a good compromise. Also, consider that, as long as you feel adventurous and depending on the interface requirements, you can locally cast from one type to another (through dynamic or static_cast, i,e, your compressed_matrix and ublas' compressed_matrix) to switch between interfaces, since there should be binary compatibility between the two types. Depending on your application though, this might be particularly insecure in many ways.

Best,
Nasos

From: pmamales_at_[hidden]
To: ublas_at_[hidden]
Date: Sat, 10 Mar 2012 23:30:33 -0500
Subject: Re: [ublas] disabling the matrix expressions form sparse matrices

Hi Naso,
Thx for responding.
I am looking into the compressed_matrix. I have resorted to some
hackery
where –by hand- defined the type to not derive from the
matrix_container
-extending this to the constructors, of course. And it works OK – there is
a lot
of useful code there.
Now, given that the ublas matrix operations are not really optimized for
performance
-although a lot of very good work is in place there - it is a bandage I am
willing to live with.
I thought of deriving privately, but then it was too much work with the
iterators and all.
The interesting thing is that, when I did it for matrix (actually had to
hold a matrix and derive from
a matrix range for leading dimension requirement reasons) I had to
explicitly derive from matrix_container
(vs2010, win7).
Hence I was hoping..
Thx again – especially on a Sat evening,
Petros

 
ps: I would like to point out that, no info
exists in the compressed_matrix for whether this is, for example,. the upper
triangular part
of a symmetric/hermitian matrix. This makes it,
unavoidably, to be used primarily for storage and element
insertion/access,
but not ready to be used for apps. I can imagine
that probably this can be accommodated w/adaptors, but I think this ties ublas
inwards
too much for broader use.
Just an opinion..
 
 

From: Nasos Iliopoulos
Sent: Saturday, March 10, 2012 8:48 PM
To: ublas_at_[hidden]
Subject: Re: [ublas] disabling the matrix expressions form sparse
matrices
 

Petro,

If you mean using the uBlas sparse matrices as
containers only and AFAIK this is not formally possible. I am sure though you
can do it through some hackery, forking or wrapping, as long as you can satisfy
binary compatibility between uBlas and vendor specific functions. Which sparse
matrix type do you need?

Best,
Nasos

> From: pmamales_at_[hidden]
> To:
ublas_at_[hidden]
> Date: Fri, 9 Mar 2012 20:35:39 -0500
>
Subject: [ublas] disabling the matrix expressions form sparse matrices
>

> Hi,
> is there a way to disable the matrix expressions of the
sparse matrices ?
> I would like to use vendor provided functions for my
calls.
> TIA,
> Petros
>
>
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