Go here: http://www.nitrc.org/frs/download.php/2871/GIFTI_Surface_Format.pdf
On page 36, it says: The application of a CoordinateSystemTransformMatrix, places the coordinates into the system shown in the table below. All coordinates are in millimeters. So sorry: You don't get to change units. But I know I'm not the only one scratching my head wondering why you want to do this. Oh, I know the occasional temptation to lie in a volume header, to elicit certain software behavior. But I've never been tempted to do it on a surface. I've scaled surfaces for real (e.g., if I had to lie in a header when segmenting a smaller mammal, to get SureFit to do the right thing). But not to get surfaces to behave properly. So I guess I'm curious. Because what you describe below seems to me to be the equivalent of taking x,y,z axes; lining out the indices and writing numbers 1/4 the size of the original marks; and then lining those through and writing the original marks down. Which means I'm almost certainly not getting what you asked. On Aug 24, 2012, at 1:47 AM, Colin Reveley wrote: > Would it be possible to shrink a surface with a scaling matrix, and then > define the mesh as being in the same space as the original. > > E.g a mesh at 1mm scaled down to eg 0.25mm and then redefined as a 1mm > surface? > > The notion here is to generate an outer and inner pair of white matter > surfaces. Of course there are issues. > > The general notion is to then treat these as white and pial surfaces, take > their mean and map white matter data using matt's method for mapping gray > matter data (scalar diffusion maps). > > This is less nuts than it sounds in marmoset because the white matter is > simple topologically and in terms of gross anatomy , particularly in the > caudal half of the brain. > > In principle there should be a mid thickness line in much of the brains white > matter. > > With a nifti you just change the units in the header. I don't appear to see a > gifti equivalent. > > Thanks > > Colin > _______________________________________________ > caret-users mailing list > [email protected] > http://brainvis.wustl.edu/mailman/listinfo/caret-users _______________________________________________ caret-users mailing list [email protected] http://brainvis.wustl.edu/mailman/listinfo/caret-users
