Patrick, You can calculate Procrustes distance between any two configuration using the procdist() function of the shapes package. https://www.rdocumentation.org/packages/shapes/versions/1.2.3/topics/procdist
M From: lv xiao [mailto:lxia...@gmail.com] Sent: Saturday, January 06, 2018 5:37 PM To: MORPHMET <morphmet@morphometrics.org> Subject: [MORPHMET] DA value calculation Dear all, Question 1: If I have a set of specimens which are object symmetry, how could I calculate directional asymmetry (DA) score for this set of specimen? I noted that after using bilat.symm function in geomorph, DA.component could be extracted, which contains two sets of coordinates. I guess DA score of the sample could be calculated from DA.component, can anyone show me the code necessary to derive DA score, whether in geomorph or any other software? Question 2: A possibly related question is how (appreciated if R code is provided) to obtain the Procrustes distance between two specimens after GPA. I think I can calculate the Procrustes distance between the original and reflected and relabled mirrors for each specimen and averaging the Procrustes distance across all specimens to obtain DA score for my entire sample. Question3: A third question which is unrelated to the previous two is that I noted that Procrustes Variance is used in Morphol.disparity function to compare morphological disparity across groups. Procrustes Variance is explained in the user manual as "the sum of the diagonal elements of the group covariance matrix." But where can I find some more detailed mathematical definition of Procrustes Variance? Thank you very much for your help! Best regards, Patrick Wen -- 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.
