I've just noticed that the problem seems to be related to freeview it
could be a bug I think. Comparing some matlab results with the ones
computed using tkmedit tool, I've just noticed that they are exactly the
same. The error arise when I'll try to move the cursor in freeview to
the requested vertex. It'll be displayed in the wrong position.

Is freeview still underdevelopment I can send to the developers the
surfaces so they can track back where the problem is.

As a proof of what I'm saying find above the tkrRAS coordinates:

contact point is located to [51.392031,-11.944675,15.952733]
tkmedit reports 111044 - [51.2886  -10.9553   17.4638]
matlab tools as well as tkmedit
but freeview reports 111044 - [5.35,-11.48,16.54]

Cheers,

g.

On Thu, 2011-05-05 at 09:03 -0400, Bruce Fischl wrote:
> can't you just do it in matlab? For 150 points, an exhaustive search 
> wouldn't be too bad.
> On Thu, 5 May 2011, Gabriele Arnulfo wrote:
> 
> > Sorry here it is.
> >
> > I need to find the nearest vertex through a script since the contacts
> > are 150 in average for each patients and any manual computation is
> > really too long to be done.  Indeed the tkmedit gives a more correct
> > answer than the matlab tools I've used , but as I said having so many
> > different points it would be a pain checking all them manually.
> >
> > Any suggestion will be appreciated.
> >
> >
> >
> > On Thu, 2011-05-05 at 08:44 -0400, Bruce Fischl wrote:
> >> Hi Gabriele,
> >>
> >> I think you forgot the attachement. I'm not sure what mesh_vertex_nearest
> >> is. If you use the tkmedit tool (find closest vertex) does that give you
> >> the correct point? If speed is not an issue you can simply do an exhaustive
> >> search, although that will be slow if you need to do it for any sizeable
> >> chunk of the surface. The way we do it internally is to build a spatial
> >> lookup table to restrict the vertices we have to search over.
> >>
> >> cheers
> >> Bruce
> >>
> >>
> >> On Thu, 5 May 2011, Gabriele Arnulfo wrote:
> >>
> >>> Dear freesurfer experts,
> >>>
> >>> my scene is as follow: i need to find the nearest vertex in the pial
> >>> surface to a subset of specified control points. I've already checked
> >>> all the transformation matrices and the points are correctly located
> >>> either in scanner RAS and in tkrRAS. Now the problem is that using
> >>> mesh_vertex_nearest freesurfer tool or dsearchn/ DelaunayTri class
> >>> matlab tools the resulting vertexes are not so correctly located as they
> >>> visually would be. I'll attach some screenshots from freeview for better
> >>> understanding.
> >>>
> >>> As you guys can easily see in the attached png ,the cursor is located at
> >>> the "nearest vertex" position while the control point, which is from the
> >>> left the second red dot, is at least located at the opposite side of the
> >>> right hemisphere. This doesn't happen for ALL the points but only for
> >>> some of them like this one. Is there a more reliable way to compute
> >>> automatically the nearest vertex for a specified control point?
> >>>
> >>> Thank in advance,
> >>>
> >>>
> >>>
> >>
> >>
> >> The information in this e-mail is intended only for the person to whom it 
> >> is
> >> addressed. If you believe this e-mail was sent to you in error and the 
> >> e-mail
> >> contains patient information, please contact the Partners Compliance 
> >> HelpLine at
> >> http://www.partners.org/complianceline . If the e-mail was sent to you in 
> >> error
> >> but does not contain patient information, please contact the sender and 
> >> properly
> >> dispose of the e-mail.
> >>
> >
> >


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