oops! I forgot to attach the files needed by these two functions... see them attached now. I hope I'm not forgetting any others...
On 1 June 2014 19:21, Anderson M. Winkler <wink...@fmrib.ox.ac.uk> wrote: > Hi Lars, > > I guess you are working with vertexwise rather than facewise data, is this > right? You'd need to compute then the area-per-vertex of the same sphere > used as the target for the interpolation, i.e., the ico7 > (surf/?h.sphere.reg in fsaverage I think). Attached is a Matlab function > that calculates this area-per-vertex (or the area-per-face )from a surface > and saves as a curvature file, in ASCII format. It reads also in ASCII, so > you need to convert first (mris_convert). To run, it's something as this: > > *srf2area lh.sphere.reg.srf ico7.area.dpv dpv* > > Then multiply either each subject area map (after interpolation), or the > average map, by 4*pi*r^2 (r should be 100), and divide the result by the > area-per-vertex from the sphere that you calculated above, and divide the > result again by the number of vertices in the sphere, which should be > 163842. To do this, use the attached rpncalc function, that also runs in > Matlab, and does simple maths in curvature files that are all of the same > size, using RPN notation > <http://en.wikipedia.org/wiki/Reverse_Polish_notation>. Inputs are also > in ASCII. To run, it should be something like this: > > rpncalc lh.white.interp.dpv 125663.706144 * ico7.area.dpv / 163842 / > lh.white.interp.corrected.dpv > > The output you can convert back to cuvature binary and load with tksurfer > or FreeView. > > Hope this helps! > > All the best, > > Anderson > > > > On 1 June 2014 16:32, Lars M. Rimol <lari...@gmail.com> wrote: > >> >> Hi Anderson, >> >> Thank you! How would you suggest I address this issue when I smooth >> these images before statistical analysis? I normally use the smoothing >> algorithm implemented in FreeSurfer (mri_surf2surf). >> >> >> >> >> -- >> yours, >> >> Lars M. Rimol, PhD >> St. Olavs Hospital >> Trondheim, >> Norway >> >> _______________________________________________ >> Freesurfer mailing list >> Freesurfer@nmr.mgh.harvard.edu >> https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer >> >> >> 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. >> >> >
dpxread.m
Description: Binary data
dpxwrite.m
Description: Binary data
srfread.m
Description: Binary data
srfwrite.m
Description: Binary data
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