morphmet
Wed, 16 Dec 2009 08:22:05 -0800
-------- Original Message -------- Subject: Re: projected or not? Date: Tue, 15 Dec 2009 20:37:56 +0000 From: F. James Rohlf <ro...@life.bio.sunysb.edu> Reply-To: ro...@life.bio.sunysb.edu To: morphmet <morphmet_modera...@morphometrics.org>It is easy to tell. Do a PCA and look at all the eigenvalues. If there a 4 zero eigenvalues (around 10^-16) for 2D data then they are in the tangent space. If there are just 3 zeros plus a small one (around 10^-8) then no. Same idea for 3D data but the number is 7.
The tps software has options for this projection. Default is to project. ------Original Message------ From: morphmet To: Morphmet Subject: projected or not? Sent: Dec 15, 2009 3:14 PM -------- Original Message -------- Subject: projected or not? Date: Tue, 15 Dec 2009 20:13:12 GMT From: Ondřej Mikula <onmik...@gmail.com> To: morphmet@morphometrics.org Dear list, although I am not new in geometric morphometrics, I am still not sure about Procrustes coordinates in outputs of popular morphometric programmes (tpsRelw, PAST). Are they already projected into the tangent space? Thanks for advice Ondrej Mikula -- Replies will be sent to the list. For more information visit http://www.morphometrics.org -------------------------------- Sent remotely by F. James Rohlf -- Replies will be sent to the list. For more information visit http://www.morphometrics.org