I'm curious: For comparison to the results in that paper, has anyone quantified the variability that results when one runs the same FS version repeatedly on the same subject, but with a different random seed each time? That is, how much of the difference is related to math libraries vs. intrinsic variability that arises from the components of FS that use a random seed?
cheers, -MH On Wed, 2012-06-20 at 10:43 -0400, Bruce Fischl wrote: > Hi Peter > > thanks for the info. Feel free to post this on one of the *many* blogs > howling for our blood :) I think that the effects in the paper reflect > default floating point settings in gcc on 32-bit vs. 64-bit, although we > haven't really investigated as it doesn't seem like a wise use of limited > resources (since no one would ever do a study that way in any case). > > Bruce > > > On Wed, 20 Jun 2012, Peter J. Molfese wrote: > > > We run things on an Xgrid cluster that is now a mixture of Macs running Snow > > Leopard (10.6.8) and Lion (10.7.x). We found the results given from > > asegstats2table and aparcstats2table are identical after running 100 > > subjects on both Mac OS X 10.7.4 and 10.6.8 with Freesurfer 5.1. I also ran > > a few subjects on the cluster and on individual computers (not on the > > cluster so to speak) and the results are identical. > > > > Best, > > Peter > > > > > > Hi, > > > > The paper entitled > > > > ?The Effects of FreeSurfer Version, Workstation Type, > > and Macintosh Operating System Version on Anatomical > > Volume and Cortical Thickness Measurements?, > > PLoSONE, Vol 7(6), e38234 (2012) > > > > may be of interest to all of you. It can be found at: > > > > http://dx.plos.org/10.1371/journal.pone.0038234 > > > > Cheers, > > Ed > > > > > > > > > _______________________________________________ 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. _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
