Nico, >From the image you attached, things seem to be coded properly. In your case, >the resulting slider file should be a 6 X 3 matrix:
1 2 3 2 3 4 3 4 5 4 5 6 5 6 7 6 7 8 As for analyses, one would first perform a generalized Procrustes analysis, including the slider information. Inputs would be the set of xy coordinates for all landmarks and semilandmarks, as well as the matrix above designating which landmarks are sliders and in what tangent directions they will slide. The analysis may be accomplished in geomorph, TPSRelw, or the Evan toolkit. From there, the aligned Procrustes residuals may be utilized as a set of shape variables for your group comparisons. As for tutorials, TPSRelw has an extensive help file, as does EVAN. Geomorph has a user guide that includes tutorial information, and is available at: www.geomorph.net<http://www.geomorph.net>. Hope this helps, 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: Nico Posnien [mailto:nico.posn...@gmail.com] Sent: Wednesday, May 6, 2015 6:29 AM To: morphmet@morphometrics.org Subject: [MORPHMET] Analysis of semilandmark data Dear all, I have a question concerning the analysis of landmark and semilandmark data in fly heads. So far I placed landmarks on 2D images. Some of these actually represent semilandmarks. I used tps Util ("Make Sliders File"; see attched picture) to generate a sliders file. In the attached picture, 1 and 8 are landmarks and 2-7 in between them are supposed to be semilandmarks. My first question is: Is this the right way to transform landmarks into semilandmarks? My second question is: What is the best (most accepted, straight-forward) way to further analyze this data? I am mainly interested in shape differences between different groups (2 species + hybrids, males and females). Which programs should be used? I saw that geomorph can handle this kind of data. Any UI software? Are there any suggestions for good tutorials? Thanks a lot for any recommendation and help! Cheers, Nico -- Nico Posnien Georg-August-University Göttingen Johann-Friedrich-Blumenbach Institute for Zoology and Anthropology Department of Developmental Biology Ernst-Caspari-Haus (GZMB) Justus-von-Liebig-Weg 11 37077 Göttingen Germany Phone: +49 (0) 55139 20817 E-mail: npos...@gwdg.de<mailto:npos...@gwdg.de> web: http://www.evolution.uni-goettingen.de/posnienlab/index.html web: http://www.uni-goettingen.de/en/44993.html -- MORPHMET may be accessed via its webpage at http://www.morphometrics.org 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 To unsubscribe from this group and stop receiving emails from it, send an email to morphmet+unsubscr...@morphometrics.org.
