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- To: eigen@xxxxxxxxxxxxxxxxxxx
- Subject: Re: [eigen] Map questions
- From: "Gael Guennebaud" <gael.guennebaud@xxxxxxxxx>
- Date: Wed, 29 Oct 2008 22:51:34 +0100
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Hi,
On Wed, Oct 29, 2008 at 9:01 PM, Cristóvão Sousa <crisjss@xxxxxxxxx> wrote:
> Hi,
>
> I would like to do something like
>
> Vector3d v;
> // v = something;
> double a[3];
> Map<Vector3d>(a) = v;
indeed, "Map<Vector3d>(a) = v;" seems to be equivalent to
"Map<Vector3d> a = v;" that is very unfortunate...
Actually the following variants works:
Map<Vector3d>(a,3) = v;
(Map<Vector3d>(a)) = v;
Map<Vector3d>(a).operator=(v);
Map<Vector3d>(a).lazyAssign(v);
Map<Vector3d> _a(a); _a = v;
Map<Vector3d>(a).start<3>() = v;
...
I could keep going like this forever, but nothing is really good and
intuitive. Perhaps this is a good motivation to resurrect the
Matrix::Map static functions.... ??? or find something else....
> Another thing that could be a little bug:
> it is currently possible to do
>
> const double a[3]={1,2,3};
> Map<Vector3d>(a).setZero();
>
> , which discards the const qualifier of a.
ok, I'll check later if we can do something for that, but there is
nothing urgent here.
cheers,
gael.