Common principal components Robust estimation 16 Partial influence function 6 Plug-in methods 6 Proportional scatter matrices 6 Asymptotic variances 4 Eigenfunctions 4 Functional data analysis 4 Hilbert-Schmidt operators 4 Kernel methods 4 Outliers 4 Partial influence functions 4 Projection-pursuit 4 Proportional model 4 Quadratic discrimination 4 Asymptotic distributions 2 Asymptotic variance 2 Detection of outliers 2 Influence functions 2 Influential observations 2 Log-likelihood ratio test 2 Mahalanobis distances 2 Method of moments 2 Minimum covariance determinant 2 Minimum volume ellipsoids 2 Multivariable systems 2 Normal distribution 2 Outlier detection 2 Principal Components 2 Projection-Pursuit 2