From: Zhang, Jason (GE, Research, consultant) <zhangj@ge...>  20070717 13:08:27

Ian, Thanks for your clarification. I didn't find the implementation for vgl_vector_2d. Sorry about that. Jason Original Message From: Ian Scott [mailto:ian.m.scott@...]=20 Sent: Tuesday, July 17, 2007 8:52 AM To: Zhang, Jason (GE, Research, consultant) Cc: vxlmaintainers@... Subject: Re: [Vxlmaintainers] Proposed addition to vgl_point_2d.h Jason I may have misunderstood you, but vgl_vector_2d (and 3d) do already have operators +=3D and *=3D, etc. You may not have spotted them since they = are not implemented as member operators but as standalone operators. Take a look at lines 100135 in vgl_vector_2d.h Ian. Zhang, Jason (GE, Research, consultant) wrote: > It is just because that a point is a geometric entity, we find in many > cases that points are used alternatively with vectors to make=20 > representation and processing tasks such as displacing and scaling=20 > more convenient to implement. In their current implementation however, > neither vgl_point nor vgl_vector has defined these operators yet. >=20 > Jason Zhang >=20 > Original Message > From: vxlmaintainersbounces@... > [mailto:vxlmaintainersbounces@...] On Behalf Of=20 > Ian Scott > Sent: Tuesday, July 17, 2007 4:34 AM > To: Wheeler, Frederick W (GE, Research);=20 > vxlmaintainers@... > Cc: Amitha Perera > Subject: Re: [Vxlmaintainers] Proposed addition to vgl_point_2d.h >=20 > I'd have to agree with Amitha here, and vote to reject the mods. >=20 > The distinction between points and vectors was an explicit design=20 > decision in vgl. At times it is annoying, especially if you are not=20 > used to it. However, there have been occasions when the strict typing=20 > has picked up mistakes in our code. >=20 > Ian. >=20 > Amitha Perera wrote: >> On Mon 16 Jul 2007, Wheeler, Frederick W (GE, Research) wrote: >>> Jason Zhang here at GE made these straightforward additions to=20 >>> vgl_point_2d.h. Is it OK to check this in? This looks like a=20 >>> nobrainer, but the fact that such simple and useful functions were=20 >>> not already in vgl make we wonder whether there is a reason to not=20 >>> have them. >> I think the reason is the distinction between points and vectors. =20 >> You >=20 >> will find vgl_vector_2d that bridges the gap. A point is a general=20 >> geometrical concept; the difference between points makes sense=20 >> only(?) >=20 >> in a metric space. >> >> In recognition of the most widely used embedding, though, there are=20 >> functions like midpoint(p1,p2,f). >> >> Amitha. >> >>  >>  >>  This SF.net email is sponsored by DB2 Express Download DB2=20 >> Express >=20 >> C  the FREE version of DB2 express and take control of your XML. No=20 >> limits. Just data. Click to get it now. >> http://sourceforge.net/powerbar/db2/ >> _______________________________________________ >> Vxlmaintainers mailing list >> Vxlmaintainers@... >> https://lists.sourceforge.net/lists/listinfo/vxlmaintainers >=20 >=20 >  >  >  > This SF.net email is sponsored by DB2 Express Download DB2 Express C  > the FREE version of DB2 express and take control of your XML. No limits. > Just data. Click to get it now. > http://sourceforge.net/powerbar/db2/ > _______________________________________________ > Vxlmaintainers mailing list > Vxlmaintainers@... > https://lists.sourceforge.net/lists/listinfo/vxlmaintainers >=20 >  >  This SF.net email is sponsored by DB2 Express Download DB2 Express > C  the FREE version of DB2 express and take control of your XML. No=20 > limits. Just data. Click to get it now. > http://sourceforge.net/powerbar/db2/ > _______________________________________________ > Vxlmaintainers mailing list > Vxlmaintainers@... > https://lists.sourceforge.net/lists/listinfo/vxlmaintainers 