Andrey, To repeat: there is no reason to expect the numbers to match identically across software packages, particularly column by column (if that is what you are examining). Even if two packages perform things identically in terms of the algebra (e.g,. GPA using TpsRelw and geomorph), the numbers may differ slightly for other reasons (post-rotation of the alignment to the principal axes of the consensus, etc.).
What is important for downstream statistical analyses is not the individual columns of numbers found from the GPA alignment, but rather the relationships of specimens in the resultant shape space. That is, how different are shapes from one another? In the case I mentioned above, if you took the aligned specimens from TpsRelw and obtained the Procrustes (Euclidean) distance matrix from them, and did the same with the aligned specimens from geomorph, and then performed a matrix correlation, the correlation would be precisely 1.0. This means the information is identical in the two superimpositions, even if they differ slightly in how the entire set is oriented relative to the X-Y axis. Incidentally, in the above case one would also find a perfect correlation between distances from the GPA-aligned specimens, those shapes rotated to their principal axes, or differences in shape found from the thin-plate spline and uniform shape components taken together. For an early discussion of these issues see Rohlf 1999. However, performing the procedure above where one set of GPA-aligned coordinates is from MorphoJ will not produce a perfect correlation of 1.0, as MorphoJ uses Full Procrustes superimposition. That means the perceived relationships between shapes is not being represented in the same manner: which of course is a known difference between full and partial Procrustes fitting. How much of a difference one finds between a full and partial Procrustes alignment is dataset dependent. Dean Dr. Dean C. Adams Professor Department of Ecology, Evolution, and Organismal Biology Department of Statistics Iowa State University www.public.iastate.edu/~dcadams/<http://www.public.iastate.edu/~dcadams/> phone: 515-294-3834 From: Andrey Lissovsky [mailto:andlis...@gmail.com] Sent: Tuesday, October 31, 2017 10:21 AM To: MORPHMET <morphmet@morphometrics.org> Cc: andlis...@gmail.com; volk...@yandex.ru Subject: Re: [MORPHMET] Procrustes fit Thank you Dean, Of course, numbers should differ. But in my case, there is no correlation between two sets. I guess that in theory the two sets should have r at least around 0.9? On Tuesday, October 31, 2017 at 5:31:51 PM UTC+3, dcadams wrote: Andrey, It is unreasonable to expect the numbers will match perfectly between these two software packages, as the way in which they perform the operations differs. First, MorphoJ uses Full Procrustes fit, whereas the TPS series, geomorph, and others use Partial Procrustes fitting. That will make a difference. Second, there may be additional differences in in how the superimponsed specimens, and thus the consensus, is aligned relative to the X-Y coordinate system. Some packages allow one to rotate the consensus and aligned specimens to their principal axes post-superimposition. That too could lead to differences. Dean Dr. Dean C. Adams Professor Department of Ecology, Evolution, and Organismal Biology Department of Statistics Iowa State University www.public.iastate.edu/~dcadams/<http://www.public.iastate.edu/~dcadams/> phone: 515-294-3834 From: Andrey Lissovsky [mailto:andl...@gmail.com<javascript:>] Sent: Tuesday, October 31, 2017 9:26 AM To: MORPHMET <morp...@morphometrics.org<javascript:>> Cc: andl...@gmail.com<javascript:>; vol...@yandex.ru<javascript:> Subject: Re: [MORPHMET] Procrustes fit Thank you, Andrea I understand that difference should be tiny, so something goes wrong. I enclose one of my tps files. Usually I check dots and commas, so the reason is probably in some different way.. It is possible that I am mixing up menu items.. Last time I use this software, the labels were different. Now I use: In MorphoJ: Preliminaries -- New Procrustes fit -- Align by principle axes then: Export dataset -- Procrustes coordinates In TPS Relw: Actions -- Consensus then: File -- Save -- Aligned specimens Is this ok? Should these chains lead to the same results? On Tuesday, October 31, 2017 at 5:04:56 PM UTC+3, alcardini wrote: Andrey, the last time I checked this (last July, I believe), differences between MorphoJ and TPSRelw were tiny and negligible. I compared MorphoJ with R in the last days, and again differences were tiny. The first thing I'd check is whether there's an issue with commas vs dots as decimal separators. If you send me the tps file, I can give a quick look. Cheers Andrea -- 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+u...@morphometrics.org<javascript:>. -- 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<mailto: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.