36 research outputs found
Inference with Linear Equality and Inequality Constraints Using R: The Package ic.infer
In linear models and multivariate normal situations, prior information in linear inequality form may be encountered, or linear inequality hypotheses may be subjected to statistical tests. R package ic.infer has been developed to support inequality-constrained estimation and testing for such situations. This article gives an overview of the principles underlying inequality-constrained inference that are far less well-known than methods for unconstrained or equality-constrained models, and describes their implementation in the package.
Generalized resolution for orthogonal arrays
The generalized word length pattern of an orthogonal array allows a ranking
of orthogonal arrays in terms of the generalized minimum aberration criterion
(Xu and Wu [Ann. Statist. 29 (2001) 1066-1077]). We provide a statistical
interpretation for the number of shortest words of an orthogonal array in terms
of sums of values (based on orthogonal coding) or sums of squared
canonical correlations (based on arbitrary coding). Directly related to these
results, we derive two versions of generalized resolution for qualitative
factors, both of which are generalizations of the generalized resolution by
Deng and Tang [Statist. Sinica 9 (1999) 1071-1082] and Tang and Deng [Ann.
Statist. 27 (1999) 1914-1926]. We provide a sufficient condition for one of
these to attain its upper bound, and we provide explicit upper bounds for two
classes of symmetric designs. Factor-wise generalized resolution values provide
useful additional detail.Comment: Published in at http://dx.doi.org/10.1214/14-AOS1205 the Annals of
Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical
Statistics (http://www.imstat.org
Multilevel Modeling Using R
Abstracts not available for BookReview
Optimal Experimental Design with R
Abstracts not available for BookReview
R Package DoE.base for Factorial Experiments
The R package DoE.base can be used for creating full factorial designs and general factorial experiments based on orthogonal arrays. Besides design creation, some analysis functionality is also available, particularly (augmented) half-normal effects plots. In addition to this specific functionality, the package provides convenience features for analyzing experimental designs and the infrastructure for a suite of further packages on designing and analyzing experiments. This infrastructure is available for use also by further design of experiments packages