In this work we address the problem of estimating mean and covariance curves when the available sample consists on aggregated functional data. Consider a population divided into sub-populations for which one wants to estimate the mean (typology) and covariance curves for each sub-population. However, it is not possible (or too expensive) to obtain sample curves for single individuals. The available data are collective curves, sum of curves of different subsets of individuals belonging to the sub-populations. We propose an estimation method based on B-splines expansion. This method is consistent and simulation studies suggest that the proposed mean estimator is suitable even with very few replications. This problem was motivated by a real problem concerning the efficient distribution of electric energy in Southeast Brazil.
Número:
19
Ano:
2007
Autor:
Ronaldo Dias
Nancy L. Garcia
Angelo Martarelli
Abstract:
Keywords:
functional data
B-splines
aggregated data
electric load monitoring
Mathematics Subject Classification 2000 (MSC 2000):
Primary 62G08; Secondary 62P30
Observação:
submitted 07/07
Arquivo: