Conventional Procrustes Approaches
نویسندگان
چکیده
Conventional Procrustes methods allow the analysis of morphology through the superimposition of one morphology onto another using the positions of landmark points. These methods are most useful for the comparison of pairs or small groups of specimens when it is of interest to describe one morphology in terms of deformation from another. When population analyses are of interest, generalized methods tend to be more appropriate. Leastsquares methods are most appropriate when change is more general and not localized, whereas robust methods are unexcelled in demonstrating localized change when it is present. Examples are given that demonstrate the relative strengths of the two approaches and comparison made with the results of a biorthogonal analysis. The algorithms used in calculating two forms of conventional Procrustes analyses, Least-Squares Theta-Rho-Analysis (LSTRA) and Resistant-Fit Theta-Rho-Analysis (RFTRA) are discussed in detail.
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