Greg, your answer is 100% perfect, I cannot add anything more. Ales On 5 December 2012 15:12, Greg Troxel <[email protected]> wrote:
> > I have a large point-cloud. I would like to convert coordinate > systems, a 7-DOF rotate, translate, and scale. > > My quick reaction is that gama isn't the right tool, since it's about > estimating coordinates given observations. If you already have an > internally-consistent point cloud, then you aren't estimating > coordinates. > > I think your problem has two sub-parts: > > estimating the rotation/translation/scale > > applying it > > Applying it is similar to datum transformation, except that datum > transformations are typically small angles. > > It may be that part of the gama code is helpful. > > Given only two control points, I would think you could > > transform the control points real coordintes to ECEF XYZ (via proj4) > > compute translation, scale > > compute/choose an orientation, because you're down a control point > > pretty easily, with the last two steps being done with a calculator > even. > > Then, you could end up with rotate and translate matrices, and apply > them with octave. > > > If you had more control points, you'd be in a least-squares situation > (and better off data wise with a harder processing problem, really :-). > > It may be that having framed the problem of multiple control points with > coordinates in two different systems, you can write code to use the > solver in gama to solve that different problem. But I'd expect the bulk > of gama to be about computing the partial derivatives of the types of > observations used in surveying. > > _______________________________________________ > Info-gama mailing list > [email protected] > https://lists.gnu.org/mailman/listinfo/info-gama > >
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