Abstract
Various concepts of mean shape previously unrelated in the literature are brought into relation. In particular, for non-manifolds, such as Kendall’s 3D shape space, this paper answers the question, for which means one may apply a two-sample test. The answer is positive if intrinsic or Ziezold means are used. The underlying general result of manifold stability of a mean on a shape space, the quotient due to an proper and isometric action of a Lie group on a Riemannian manifold, blends the slice theorem from differential geometry with the statistics of shape. For 3D Procrustes means, however, a counterexample is given. To further elucidate on subtleties of means, for spheres and Kendall’s shape spaces, a first-order relationship between intrinsic, residual/Procrustean and extrinsic/Ziezold means is derived stating that for high concentration the latter approximately divides the (generalized) geodesic segment between the former two by the ratio 1:3. This fact, consequences of coordinate choices for the power of tests and other details, e.g. that extrinsic Schoenberg means may increase dimension are discussed and illustrated by simulations and exemplary datasets.
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References
Afsari, B. (2011). Riemannian L p center of mass: existence, uniqueness, and convexity. Proceedings of the American Mathematical Society, 139, 655–773.
Anderson, T. (2003). An introduction to multivariate statistical analysis (3rd ed.). New York: Wiley.
Bandulasiri, A., Patrangenaru, V. (2005). Algorithms for nonparametric inference on shape manifolds. Proceedings of JSM 2005 Minneapolis, MN, 1617–1622.
Bhattacharya A. (2008) Statistical analysis on manifolds: A nonparametric approach for inference on shape spaces. Sankhya, Series A, 70(2): 223–266
Bhattacharya R. N., Patrangenaru V. (2003) Large sample theory of intrinsic and extrinsic sample means on manifolds I. The Annals of Statistics, 31(1): 1–29
Bhattacharya R. N., Patrangenaru V. (2005) Large sample theory of intrinsic and extrinsic sample means on manifolds II. The Annals of Statistics, 33(3): 1225–1259
Billera L., Holmes S., Holmes S., Holmes S. (2001) Geometry of the space of phylogenetic trees. Advances in Applied Mathematics, 27(4): 733–767
Bredon, G. E. (1972). Introduction to compact transformation groups. In Pure and applied mathematics (Vol. 46). New York: Academic Press.
Choquet G. (1954) Theory of capacities. Annales de l’Institut de Fourier, 5: 131–295
Dryden I. L., Mardia K. V. (1998) Statistical shape analysis. Wiley, Chichester
Dryden, I. L., Kume, A., Le., H., Wood, A. T. A. (2008). A multidimensional scaling approach to shape analysis (to appear).
Fréchet M. (1948) Les éléments aléatoires de nature quelconque dans un espace distancié. 10(4): 215–310
Gower J. C. (1975) Generalized Procrustes analysis. Psychometrika, 40(33–51): 40 33–51
Hendriks H., Landsman Z. (1996) Asymptotic behaviour of sample mean location for manifolds. Statistics and Probability Letters, 26: 169–178
Hendriks H., Landsman Z. (1998) Mean location and sample mean location on manifolds: asymptotics, tests, confidence regions. Journal of Multivariate Analysis, 67: 227–243
Hendriks H., Landsman Z., Ruymgaart F. (1996) Asymptotic behaviour of sample mean direction for spheres. Journal of Multivariate Analysis, 59: 141–152
Hotz, T., Huckemann, S., Le, H., Marron, J. S., Mattingly, J. C., Miller, E., Nolen, J., Owen, M., Patrangenaru, V., Skwerer, S. (2012). Sticky central limit theorems on open books. arXiv.org, 1202.4267 [math.PR] [math.MG] [math.ST].
Huckemann, S. (2010). R-package for intrinsic statistical analysis of shapes. http://www.mathematik.uni-kassel.de/~huckeman/software/ishapes_1.0.tar.gz.
Huckemann S. (2011) Inference on 3D Procrustes means: Tree boles growth, rank-deficient diffusion tensors and perturbation models. Scandinavian Journal of Statistics, 38(3): 424–446
Huckemann S., Ziezold H. (2006) Principal component analysis for Riemannian manifolds with an application to triangular shape spaces. Advances of Applied Probability (SGSA), 38(2): 299–319
Huckemann S., Hotz T., Munk A. (2010) Intrinsic MANOVA for Riemannian manifolds with an application to Kendall’s space of planar shapes. IEEE Transactions on Pattern Analysis and Machine Intelligence, 32(4): 593–603
Huckemann S., Hotz T., Munk A. (2010) Intrinsic shape analysis: Geodesic principal component analysis for Riemannian manifolds modulo Lie group actions (with discussion). Statistica Sinica, 20(1): 1–100
Jupp P. E. (1988) Residuals for directional data. Journal of Applied Statistics, 15(2): 137–147
Karcher, H. (1977). Riemannian center of mass and mollifier smoothing. Communications on Pure and Applied Mathematics, 509–541.
Kendall, D. (1974). Foundations of a theory of random sets. In Stochastic geometry, tribute memory Rollo Davidson (pp. 322–376). New York: Wiley.
Kendall, D. G., Barden, D., Carne, T. K., Le, H. (1999). Shape and shape theory. Chichester: Wiley.
Kendall W. S. (1990) Probability, convexity, and harmonic maps with small image I: Uniqueness and fine existence. Proceedings of the London Mathematical Society, 61: 371–406
Kent, J., Hotz, T., Huckemann, S., Miller, E. (2011). The topology and geometry of projective shape spaces (in preparation).
Klassen, E., Srivastava, A., Mio, W., Joshi, S. (2004, March). Analysis on planar shapes using geodesic paths on shape spaces. IEEE Transactions on Pattern Analysis and Machine Intelligence, 26(3), 372–383.
Kobayashi, S., Nomizu, K. (1963). Foundations of differential geometry (Vol. I). Chichester: Wiley.
Kobayashi, S., Nomizu, K. (1969). Foundations of differential geometry (Vol. II). Chichester: Wiley.
Krim, H., Yezzi, A. J. J. E. (2006). Statistics and analysis of shapes. In Modeling and Simulation in Science, Engineering and Technology. Boston: Birkhäuser.
Le H. (2001) Locating Fréchet means with an application to shape spaces. Advances of Applied Probability (SGSA), 33(2): 324–338
Le H. (2004) Estimation of Riemannian barycenters. LMS Journal of Computation and Mathematics, 7: 193–200
Lehmann, E. L. (1997). Testing statistical hypotheses. In Springer texts in statistics. New York: Springer.
Mardia, K., Patrangenaru,. V. (2001). On affine and projective shape data analysis. In K. V. Mardia, R. G. Aykroyd (Eds.), Proceedings of the 20th LASR Workshop on functional and spatial data analysis (pp. 39–45).
Mardia K., Patrangenaru V. (2005) Directions and projective shapes. The Annals of Statistics, 33: 1666–1699
Matheron, G. (1975). Random sets and integral geometry. In Wiley series in probability and mathematical statistics. New York: Wiley.
Nash J. (1956) The imbedding problem for Riemannian manifolds. The Annals of Mathematics, 63: 20–63
Palais, R. S. (1961). On the existence of slices for actions of non-compact Lie groups. The Annals of Mathematics 2nd Series, 73(2), 295–323
Schmidt, F. R., Clausen, M., Cremers, D. (2006). Shape matching by variational computation of geodesics on a manifold. In Pattern recognition (Proceedings DAGM), LNCS (Vol. 4174, pp. 142–151). Berlin: Springer.
Small, C. G. (1996). The statistical theory of shape. New York: Springer.
Zahn C., Roskies R. (1972) Fourier descriptors for plane closed curves. IEEE Transactions on Computers, C 21: 269–281
Ziezold, H. (1977). Expected figures and a strong law of large numbers for random elements in quasi-metric spaces. In Transaction of the 7th Prague conference on information theory, statistical decision function and random processes, A, pp. 591–602.
Ziezold, H. (1994). Mean figures and mean shapes applied to biological figure and shape distributions in the plane. Biometrical Journal, 36, 491–510
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Huckemann, S.F. On the meaning of mean shape: manifold stability, locus and the two sample test. Ann Inst Stat Math 64, 1227–1259 (2012). https://doi.org/10.1007/s10463-012-0352-2
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DOI: https://doi.org/10.1007/s10463-012-0352-2