 |
 |
Hi, No, that's not the implementation that we use. See: http://www.fmrib.ox.ac.uk/analysis/techrep/tr99mj1/tr99mj1/node5.html All the best, Mark On 31 Jan 2012, at 22:56, Yiou Li wrote: > Hi Mark, > > Thanks for the prompt feedback! As I understand, the rmsdiff measure > is invariant to the order of transform matrices just as |X1 - X2|^2 is > symmetric to both variables? > > Thanks! > Leo > > On Tue, Jan 31, 2012 at 2:44 PM, Mark Jenkinson <[log in to unmask]> wrote: >> Dear Leo, >> >> There is no right answer. >> The two different ways just average over a slightly different >> spherical ROIs. However, the difference will be pretty minor >> and I can't think of an example where these small differences >> would matter. >> >> All the best, >> Mark >> >> >> >> On 31 Jan 2012, at 22:08, Yiou Li wrote: >> >>> Hi Mark, >>> >>> I want to use rmsdiff to measure the difference between image X1 and >>> X2 in terms of affine linear transformation, to do that, I ran flirt >>> to register X1 to X2, taking X2 as reference image and get the >>> transformation xmat_1_to_2, now I got two slightly different number by >>> running: >>> >>> 1. rmsdiff xmat_identity xmat_1_to_2 X2 >>> 2. rmsdiff xmat_1_to_2 xmat_identity X2 >>> >>> Can you please advise which one is the correct order in this case? >>> >>> Thanks in advance! >>> Leo >>> >