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<DIV><FONT size=2>Hi,</FONT></DIV>
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<DIV><FONT size=2>I have just come across this community and seek some
help. If you read on, you might find some useful tools among my stuff too,
although they are probably covered by sea-mat already.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>I am developing a matlab toolbox for human scalp
electroencephalograpy (EEG) topographic mapping, among other things. See
<A href="http://eeg.sourceforge.net">http://eeg.sourceforge.net</A> - there are
some useful functions among it.</FONT></DIV>
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<DIV><FONT size=2>I would like to ask a couple of things of this
community.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>1. I wonder if anyone has a matlab function for fitting
a tesselation to an object?</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>For example, I would like to tesselate magnetic resonance
images (MRI) of the human head. Commercial programs often use a
shrink-wrap technique. This involves creating a tesselated sphere larger
than the head and then moving the vertices toward the head until they reach a
scalp intensity threshold in the MRI image volume. They also incorporate
some vertex "adhesion" or nearest neighbour distance and/or angle and/or
intersection restrictions ("smoothness").</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>2. </FONT><FONT size=2>I am also interested in
development of spherical or realistic spline Laplacian routines in matlab.
My work involves interpolating the electric potential over the scalp, often with
surface contours. Matlab is frustrating because the contours can be so
damn accurate they look sharp and nasty, rather than nice smooth curves. I
would be eternally grateful if you can offer any advice on this
matter.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>If any would like Laplacian functions for a mesh, my toolbox
above has a Laplacian routine - called mesh_laplacian.m and also an
interpolation function that minimises the Laplacian - the .m files contain a
journal reference. The results are quite nice, but I haven't yet tried to
contour it and I'm afraid the matlab tools for this will not do a nice
job.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>There are also some simple functions for tesselating a sphere
of any radius, fitting irregular vertices to a sphere or ellipse and visualizing
scalar values on 3D surfaces (using patch). If you would like more
information, see the website above or ask me.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>I write to this list with the view that ocean and weather
system math, computing and visualization is very similar to electric
current/potential for the human head.</FONT></DIV>
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<DIV><FONT size=2>Thankyou for your consideration.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>Kind regards, Darren</FONT></DIV>
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