Journal of Statistical Software http://www.jstatsoft.org/rss Thu, 02 Sep 2010 21:26:30 GMT Thu, 02 Sep 2010 21:26:30 GMT Most recent publications from the Journal of Statistical Software LinkCluE: A MATLAB Package for Link-Based Cluster Ensembles http://www.jstatsoft.org/v36/i09/paper Vol. 36, Issue 9, Aug 2010

Abstract:

Cluster ensembles have emerged as a powerful meta-learning paradigm that provides improved accuracy and robustness by aggregating several input data clusterings. In particular, link-based similarity methods have recently been introduced with superior performance to the conventional co-association approach. This paper presents a MATLAB package, LinkCluE, that implements the link-based cluster ensemble framework. A variety of functional methods for evaluating clustering results, based on both internal and external criteria, are also provided. Additionally, the underlying algorithms together with the sample uses of the package with interesting real and synthetic datasets are demonstrated herein.

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Tue, 31 Aug 2010 07:00:00 GMT /v36/i09 Natthakan Iam-on, Simon Garrett
vrmlgen: An R Package for 3D Data Visualization on the Web http://www.jstatsoft.org/v36/i08/paper Vol. 36, Issue 8, Aug 2010

Abstract:

The 3-dimensional representation and inspection of complex data is a frequently used strategy in many data analysis domains. Existing data mining software often lacks functionality that would enable users to explore 3D data interactively, especially if one wishes to make dynamic graphical representations directly viewable on the web.

In this paper we present vrmlgen, a software package for the statistical programming language R to create 3D data visualizations in web formats like the Virtual Reality Markup Language (VRML) and LiveGraphics3D. vrmlgen can be used to generate 3D charts and bar plots, scatter plots with density estimation contour surfaces, and visualizations of height maps, 3D object models and parametric functions. For greater flexibility, the user can also access low-level plotting methods through a unified interface and freely group different function calls together to create new higher-level plotting methods. Additionally, we present a web tool allowing users to visualize 3D data online and test some of vrmlgen's features without the need to install any software on their computer.

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Tue, 31 Aug 2010 07:00:00 GMT /v36/i08 Enrico Glaab, Jonathan M. Garibaldi, Natalio Krasnogor
BUGS Code for Item Response Theory http://www.jstatsoft.org/v36/c01/paper Vol. 36, Code Snippet 1, Aug 2010

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Tue, 31 Aug 2010 07:00:00 GMT /v36/c01 S. McKay Curtis
Graphics for Statistics and Data Analysis with R http://www.jstatsoft.org/v36/b03/paper Vol. 36, Book Review 3, Sep 2010

Graphics for Statistics and Data Analysis with R
Kevin J. Keen
Chapman and Hall/CRC, 2010
ISBN: 9781584880875

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Wed, 01 Sep 2010 07:00:00 GMT /v36/b03 Hadley Wickham, Garrett Grolemund
R in a Nutshell http://www.jstatsoft.org/v36/b02/paper Vol. 36, Book Review 2, Aug 2010

R in a Nutshell
Joseph Adler
O'Reilly, 2010
ISBN: 978-0-596-80170-0

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Thu, 19 Aug 2010 07:00:00 GMT /v36/b02 Chee Kian Leong
Bayesian Analysis for Population Ecology http://www.jstatsoft.org/v36/b01/paper Vol. 36, Book Review 1, Aug 2010

Bayesian Analysis for Population Ecology
Ruth King, Byron J. T. Morgan, Olivier Gimenez, Stephen P. Brooks
Chapman and Hall/CRC, 2010
ISBN: 978-1-4398-1187-0

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Sun, 08 Aug 2010 07:00:00 GMT /v36/b01 Joseph Hilbe
depmixS4: An R Package for Hidden Markov Models http://www.jstatsoft.org/v36/i07/paper Vol. 36, Issue 7, Aug 2010

Abstract:

depmixS4 implements a general framework for defining and estimating dependent mixture models in the R programming language. This includes standard Markov models, latent/hidden Markov models, and latent class and finite mixture distribution models. The models can be fitted on mixed multivariate data with distributions from the glm family, the (logistic) multinomial, or the multivariate normal distribution. Other distributions can be added easily, and an example is provided with the exgaus distribution. Parameters are estimated by the expectation-maximization (EM) algorithm or, when (linear) constraints are imposed on the parameters, by direct numerical optimization with the Rsolnp or Rdonlp2 routines.

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Thu, 05 Aug 2010 07:00:00 GMT /v36/i07 Ingmar Visser, Maarten Speekenbrink
amei: An R Package for the Adaptive Management of Epidemiological Interventions http://www.jstatsoft.org/v36/i06/paper Vol. 36, Issue 6, Aug 2010

Abstract:

The amei package for R is a tool that provides a flexible statistical framework for generating optimal epidemiological interventions that are designed to minimize the total expected cost of an emerging epidemic. Uncertainty regarding the underlying disease parameters is propagated through to the decision process via Bayesian posterior inference. The strategies produced through this framework are adaptive: vaccination schedules are iteratively adjusted to reflect the anticipated trajectory of the epidemic given the current population state and updated parameter estimates. This document briefly covers the background and methodology underpinning the implementation provided by the package and contains extensive examples showing the functions and methods in action.

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Thu, 05 Aug 2010 07:00:00 GMT /v36/i06 Robert B. Gramacy, Marc Mangel, Leah R. Johnson, Daniel Merl
tolerance: An R Package for Estimating Tolerance Intervals http://www.jstatsoft.org/v36/i05/paper Vol. 36, Issue 5, Aug 2010

Abstract:

The tolerance package for R provides a set of functions for estimating and plotting tolerance limits. This package provides a wide-range of functions for estimating discrete and continuous tolerance intervals as well as for estimating regression tolerance intervals. An additional tool of the tolerance package is the plotting capability for the univariate and regression settings as well as for the multivariate normal setting. The tolerance package's capabilities are illustrated using simulated data sets. Formulas used for the estimation procedures are also presented.

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Thu, 05 Aug 2010 07:00:00 GMT /v36/i05 Derek S. Young
On Simulation of Manifold Indexed Fractional Gaussian Fields http://www.jstatsoft.org/v36/i04/paper Vol. 36, Issue 4, Aug 2010

Abstract:

To simulate fractional Brownian motion indexed by a manifold poses serious numerical problems: storage, computing time and choice of an appropriate grid. We propose an effective and fast method, valid not only for fractional Brownian fields indexed by a manifold, but for any Gaussian fields indexed by a manifold. The performance of our method is illustrated with different manifolds (sphere, hyperboloid).

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Thu, 05 Aug 2010 07:00:00 GMT /v36/i04 Alexandre Brouste, Jacques Istas, Sophie Lambert-Lacroix
Conducting Meta-Analyses in R with the metafor Package http://www.jstatsoft.org/v36/i03/paper Vol. 36, Issue 3, Aug 2010

Abstract:

The metafor package provides functions for conducting meta-analyses in R. The package includes functions for fitting the meta-analytic fixed- and random-effects models and allows for the inclusion of moderators variables (study-level covariates) in these models. Meta-regression analyses with continuous and categorical moderators can be conducted in this way. Functions for the Mantel-Haenszel and Peto's one-step method for meta-analyses of 2 x 2 table data are also available. Finally, the package provides various plot functions (for example, for forest, funnel, and radial plots) and functions for assessing the model fit, for obtaining case diagnostics, and for tests of publication bias.

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Thu, 05 Aug 2010 07:00:00 GMT /v36/i03 Wolfgang Viechtbauer
Exact and Asymptotic Weighted Logrank Tests for Interval Censored Data: The interval R Package http://www.jstatsoft.org/v36/i02/paper Vol. 36, Issue 2, Aug 2010

Abstract:

For right-censored data perhaps the most commonly used tests are weighted logrank tests, such as the logrank and Wilcoxon-type tests. In this paper we review several generalizations of those weighted logrank tests to interval-censored data and present an R package, interval, to implement many of them. The interval package depends on the perm package, also presented here, which performs exact and asymptotic linear permutation tests. The perm package performs many of the tests included in the already available coin package, and provides an independent validation of coin. We review analysis methods for interval-censored data, and we describe and show how to use the interval and perm packages.

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Thu, 05 Aug 2010 07:00:00 GMT /v36/i02 Michael P. Fay, Pamela A. Shaw
Zero-Coupon Yield Curve Estimation with the Package termstrc http://www.jstatsoft.org/v36/i01/paper Vol. 36, Issue 1, Aug 2010

Abstract:

Since zero-coupon rates are rarely directly observable, they have to be estimated from market data. In this paper we review several widely-used parametric term structure estimation methods. We propose a weighted constrained optimization procedure with analytical gradients and a globally optimal start parameter search algorithm. Moreover, we introduce the R package termstrc, which offers a wide range of functions for term structure estimation based on static and dynamic coupon bond and yield data sets. It provides extensive summary statistics and plots to compare the results of the different estimation methods. We illustrate the application of the package through practical examples using market data from European government bonds and yields.

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Thu, 05 Aug 2010 07:00:00 GMT /v36/i01 Josef Hayden, Robert Ferstl
ggplot2: Elegant Graphics for Data Analysis http://www.jstatsoft.org/v35/b01/paper Vol. 35, Book Review 1, Jul 2010

ggplot2: Elegant Graphics for Data Analysis
Hadley Wickham
Springer-Verlag, 2009
ISBN: 978-0-387-98140-6

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Fri, 30 Jul 2010 07:00:00 GMT /v35/b01 Pedro M. Valero-Mora
PypeR, A Python Package for Using R in Python http://www.jstatsoft.org/v35/c02/paper Vol. 35, Code Snippet 2, Jul 2010

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Fri, 30 Jul 2010 07:00:00 GMT /v35/c02 Xiao-Qin Xia, Yipeng Wang, Michael McClelland