A Parametric Approach for Dealing with Compositional Rounded Zeros   总被引：2，自引：0，他引：2  

Javier Palarea-Albaladejo  Josep A. Martín-Fernández  Juan Gómez-García 《Mathematical Geology》2007,39(7):625-645

In this work, a parametric approach for replacing data below the detection limit, also known as rounded zeros, in compositional data sets is proposed. Compositional rounded zeros correspond to small proportions of some whole that cannot be reliably detected by the analytical instruments under given operating conditions. This kind of zeros appear frequently in the data collection process in geosciences. They must be treated in an adequate way before some multivariate analysis can be applied. Our procedure results from a modification of the Expectation-Maximization (EM) algorithm and is based on the additive log-ratio transformation. Its coherence with the nature of compositional data and with basic operations in the simplex sample space is checked. Using real data sets, we find that this approach improves other parametric and non-parametric techniques for compositional rounded zeros.  相似文献   

Weighting of Parts in Compositional Data Analysis: Advances and Applications     

Hron  Karel  Menafoglio  Alessandra  Palarea-Albaladejo  Javier  Filzmoser  Peter  Talská  Renáta  Egozcue  Juan José 《Mathematical Geosciences》2022,54(1):71-93

Mathematical Geosciences - It often occurs in practice that it is sensible to give different weights to the variables involved in a multivariate data analysis—and the same holds for...  相似文献   

Analysing Pairwise Logratios Revisited     

Hron  Karel  Coenders  Germá  Filzmoser  Peter  Palarea-Albaladejo  Javier  Faměra  Martin  Matys Grygar  Tomáš 《Mathematical Geosciences》2021,53(7):1643-1666

Mathematical Geosciences - Even though the logratio methodology provides a range of both generic, mostly exploratory, and purpose-built coordinate representations of compositional data, simple...  相似文献