From: jhrwalter (walter_at_[hidden])
Date: 2001-12-10 04:26:02
--- In boost_at_y..., Toon Knapen <toon.knapen_at_s...> wrote:
> > This is indeed an alternative. matrix_range should be an suited
> > submatrix adaptor (with a poor name?).
>
>
> > [and in another thread]
> > matrix_range is well suited to address a sub matrix of an
existing
> > matrix. But one has to consider carefully, what code a compiler
emits
> > with this additional indirection, AFAIK
>
>
> but matrix_range does not feature a resize(size_type,size_type).
> The idea would be that you can constantly resize the adaptor
> (matrix_range) as long as it is smaller or equal in size to the
matrix
> it originates from.
I usually construct a new adaptor, for example:
matrix<double> m (size, size);
for (int i = 0; i < size; ++ i) {
matrix_range<matrix<double> > mr (m, range (0, i), range (0, i));
...
}
> > [and yet in another thread]
> > Correct. matrix_range checks it's dimensions against the
dimensions
> > of the underlying matrix.
> I can't find that, the constructors e.g. looks like :
>
> NUMERICS_INLINE
> matrix_range (matrix_type &data, const range &r1, const range
&r2):
> data_ (data), r1_ (r1), r2_ (r2) {}
Oops. The checks are deferred until element access or iterator
dereference. Is that too late?
Regards
Joerg