
Ublas : 
Subject: Re: [ublas] Matrix view over a bunch of ublas::vector's
From: Jesse Manning (manning.jesse_at_[hidden])
Date: 20100624 12:30:34
Since matrix_row and matrix_column both implement the vector_expression
concept just like ublas::vector does then the same code should be able to
operate on both transparently as long as the functions are coded to do work
on vector_expression objects instead of ublas::vector objects.
On Thu, Jun 24, 2010 at 12:11 PM, dariomt <dariomt_at_[hidden]> wrote:
> > On Thu, Jun 24, 2010 at 13:21, <dariomt <at> gmail.com> wrote:
> > Hi list,Suppose I have an algorithm that works over a matrix expression.I
> also
> have a bunch of M ublas::vector's all of size N, each representing a row of
> a
> matrix.Is it possible to create a 'view' over those vectors to pass it to
> the
> algo as a MxN matrix expression?In this context a 'view' means that I don't
> need
> to copy the data in the vectors into a ublas::matrixAlso N >> M, both
> determined
> at runtime (i.e. N and M are not compile time constants).Thanks!
>
>
> Jesse Manning <manning.jesse <at> gmail.com> writes:
>
> >
> >
> > I'm not sure the exact layout of your code but as an alternative you
> could
> store your vectors as a matrix instead of individual vectors. This will
> allow
> you to work on the matrix as a whole easily and you could use
> matrix_row/matrix_column view classes to operate on the individual vectors
> inside the matrix when needed since both of these implement the
> vector_expression concept. This is essentially what I am doing in one of my
> projects and it seems to work well.
>
> I already thought about that, but it means that those parts of code must
> work
> with storage coming from an ublas::vector or from a row in a ublas::matrix,
> and
> that is not possible at the moment.
>
> Thanks anyway!
>
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