Will update and try again. That sounds - without being too hopeful - like it might solve my problem. If not, I'll come back with better details.
I would also like the clarification on the point Andrea has asked about. That sounds like a concerning issue for what I'm trying to do with this. Thanks! Ari On Thu, Feb 18, 2016 at 4:06 PM, Collyer, Michael <michael.coll...@wku.edu> wrote: > Ari, > > If you are using geomorph, you might want to update it via GitHub. Just a > few days ago we updated the software with some bug fixes for surface points > (one bug fix was for assuring non-arbitrary directions in PC planes for > tangents of surface points). If you are unsure how to do that, look at the > post by Dean Adams on 15 February 2016. > > Beyond that, you are asking for assistance without defining (1) how you > are sliding your landmarks (minimizing Procrustes Distance or Bending > Energy) or (2) other specifics that might be important (package within R, > maybe other inputs that might be important, such as the relative numbers of > fixed landmarks and semilandmarks, etc.). > > Contrary to your logic, subsetting your sample could have an effect. Your > mean configuration would change in each of the subsamples, from the mean of > your original sample, thus changing the reference configuration used in the > separate GPAs performed. The reference configuration has a prominent role > in the sliding of landmarks. > > With the information you provided, t is not possible to discern among user > error, program error, or analytical artifact. > > Mike > > Michael Collyer > > Associate Professor > Biostatistics > Department of Biology > Western Kentucky University > 1906 College Heights Blvd. #11080 > Bowling Green, KY 42101-1080 > Phone: 270-745-8765; Fax: 270-745-6856 > Email: michael.coll...@wku.edu > > On Feb 18, 2016, at 9:43 AM, Ariadne Schulz <ariadne.sch...@gmail.com> > wrote: > > Hello all, > > I'm having a bit of a semilandmark problem. I'm working on 3D surfaces > with semilandmarks. (Profuse thank yous to Emma for writing the scripts for > that.) The issue I'm having I think is occurring in the sliding. When I do > populations alone everything seems normal. The semilandmarks do not appear > to be going off the surface defined for them, but if I try to do more than > one population at once several of the semilandmarks slide off the surface > so my PCs get rather distorted. Based on the few individuals from different > populations I've looked at I think I do have interpopulation variation but > I wouldn't expect that to influence the sliding of semilandmarks. Has > anyone else encountered an issue like this with either 2D or 3D > semilandmarks? As with all things R I expect the answer will be something > like me omitting a comma somewhere so any suggestions you might have are > welcome. > > Best, > Ari > > -- > MORPHMET may be accessed via its webpage at http://www.morphometrics.org > --- > You received this message because you are subscribed to the Google Groups > "MORPHMET" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to morphmet+unsubscr...@morphometrics.org. > > > -- MORPHMET may be accessed via its webpage at http://www.morphometrics.org --- You received this message because you are subscribed to the Google Groups "MORPHMET" group. To unsubscribe from this group and stop receiving emails from it, send an email to morphmet+unsubscr...@morphometrics.org.
