Subject: Re: [boost] different matrix library?
From: Rutger ter Borg (rutger_at_[hidden])
Date: 2009-08-18 06:37:37
Edward Grace wrote:
>
> Hi Rutger,
>
> I'm not sure I understand. Perhaps because, I'm guessing, you don't
> understand what the
>
> B(tgt{:}) = A(src{:})
>
> is doing -- it took me a while to figure out when I first saw it.
> Can you confirm that you are happy with the following - src on the
> left tgt on the right?
I think I understood. Although the statement looks powerful, I think it is a
bit of "cheating" because setting up the index vectors tgt and src is done
in a loop, by dimension.
> How would *you* do this, elegantly, in C++? That's a genuine
> question -- I'm curious because, quite frankly, it's foxed me for
> ages and I would like to do this in C++! ;-)
I would say this is a typical example that I would solve by recursion. For
the case of a nested std::vector, please see attached. Uncomment lines in
main for other dimensions, to see that working. Add some more goodies for
sizes and stuff and you're done for any arbitrary nesting and/or dimension
of data. Not sure if it is the the most elegant solution, though.
Cheers,
Rutger