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Full-Text Articles in Computer Sciences

Panjen: An R Package For Ranking Transformations In A Linear Regression, Cathrine Ulla Jensen, Toke Emil Panduro Jul 2018

Panjen: An R Package For Ranking Transformations In A Linear Regression, Cathrine Ulla Jensen, Toke Emil Panduro

The R Journal

PanJen is an R-package for ranking transformations in linear regressions. It provides users with the ability to explore the relationship between a dependent variable and its independent variables. The package offers an easy and data-driven way to choose a functional form in multiple linear regression models by comparing a range of parametric transformations. The parametric functional forms are benchmarked against each other and a non-parametric transformation. The package allows users to generate plots that show the relation between a covariate and the dependent variable. Furthermore, PanJen will enable users to specify specific functional transformations, driven by a priori and theory-based …


Arco: An R Package To Estimate Artificial Counterfactuals, Yuri R. Fonseca, Ricardo P. Masini, Marcelo C. Medeiros, Gabriel F.R. Vasconcelos Jul 2018

Arco: An R Package To Estimate Artificial Counterfactuals, Yuri R. Fonseca, Ricardo P. Masini, Marcelo C. Medeiros, Gabriel F.R. Vasconcelos

The R Journal

In this paper we introduce the ArCo package for R which consists of a set of functions to implement the the Artificial Counterfactual (ArCo) methodology to estimate causal effects of an intervention (treatment) on aggregated data and when a control group is not necessarily available. The ArCo method is a two-step procedure, where in the first stage a counterfactual is estimated from a large panel of time series from a pool of untreated peers. In the second-stage, the average treatment effect over the post-intervention sample is computed. Standard inferential procedures are available. The package is illustrated with both simulated and …


Infotrad: An R Package For Estimating The Probability Of Informed Trading, Duygu Çelik, Murat Tiniç Jul 2018

Infotrad: An R Package For Estimating The Probability Of Informed Trading, Duygu Çelik, Murat Tiniç

The R Journal

The purpose of this paper is to introduce the R package InfoTrad for estimating the probability of informed trading (PIN) initially proposed by Easley et al. (1996). PIN is a popular information asymmetry measure that proxies the proportion of informed traders in the market. This study provides a short survey on alternative estimation techniques for the PIN. There are many problems documented in the existing literature in estimating PIN. InfoTrad package aims to address two problems. First, the sequential trading structure proposed by Easley et al. (1996) and later extended by Easley et al. (2002) is prone to sample selection …


Conference Report: Erum 2018, Gergely Daróczi Jul 2018

Conference Report: Erum 2018, Gergely Daróczi

The R Journal

The European R Users Meeting (eRum) is an international conference that aims at bringing together users of the R language living in Europe– in the years when the useR! conference is hosted outside of the continent.

The first eRum conference was held in 2016 in Poznan, Poland with around 250 attendees and 20 sessions spanning over 3 days, including more than 80 speakers. Around that time, we also held a smaller conference in Budapest: the first satRday event happened with 25 speakers and almost 200 attendees from 19 countries in 2016.

The eRum 2018 conference is heritage of these two …


Realvams: An R Package For Fitting A Multivariate Value-Added Model (Vam), Jennifer Broatch, Jennifer Green, Andrew Karl Jul 2018

Realvams: An R Package For Fitting A Multivariate Value-Added Model (Vam), Jennifer Broatch, Jennifer Green, Andrew Karl

The R Journal

We present RealVAMS, an R package for fitting a generalized linear mixed model to multimembership data with partially crossed and partially nested random effects. RealVAMS utilizes a multivariate generalized linear mixed model with pseudo-likelihood approximation for fitting normally distributed continuous response(s) jointly with a binary outcome. In an educational context, the model is referred to as a multidimensional value-added model, which extends previous theory to estimate the relationships between potential teacher contributions toward different student outcomes and to allow the consideration of a binary, real-world outcome such as graduation. The simultaneous joint modeling of continuous and binary outcomes was not …


Approximating The Sum Of Independent Non-Identical Binomial Random Variables, Boxiang Liu, Thomas Quertermous Jul 2018

Approximating The Sum Of Independent Non-Identical Binomial Random Variables, Boxiang Liu, Thomas Quertermous

The R Journal

The distribution of the sum of independent non-identical binomial random variables is frequently encountered in areas such as genomics, healthcare, and operations research. Analytical solutions for the density and distribution are usually cumbersome to find and difficult to compute. Several methods have been developed to approximate the distribution, among which is the saddlepoint approximation. However, implementation of the saddlepoint approximation is non-trivial. In this paper, we implement the saddlepoint approximation in the sinib package and provide two examples to illustrate its usage. One example uses simulated data while the other uses real-world healthcare data. The sinib package addresses the gap …


Editorial, John Verzani Jul 2018

Editorial, John Verzani

The R Journal

On behalf of the Editorial Board, I am pleased to present Volume 10, Issue 1 of the R Journal. This issue contains 36 contributed articles. The majority of which cover new or newly enhanced packages on CRAN.


Nonparametric Independence Tests And K-Sample Tests For Large Sample Sizes Using Package Hhg, Barak Brill, Yair Heller, Ruth Heller Jul 2018

Nonparametric Independence Tests And K-Sample Tests For Large Sample Sizes Using Package Hhg, Barak Brill, Yair Heller, Ruth Heller

The R Journal

Nonparametric tests of independence and k-sample tests are ubiquitous in modern applications, but they are typically computationally expensive. We present a family of nonparametric tests that are computationally efficient and powerful for detecting any type of dependence between a pair of univariate random variables. The computational complexity of the suggested tests is sub-quadratic in sample size, allowing calculation of test statistics for millions of observations. We survey both algorithms and the HHG package in which they are implemented, with usage examples showing the implementation of the proposed tests for both the independence case and the k-sample problem. The tests are …


Dimred And Coranking - Unifying Dimensionality Reduction In R, Guido Kraemer, Markus Reichstein, Miguel D. Mahecha Jul 2018

Dimred And Coranking - Unifying Dimensionality Reduction In R, Guido Kraemer, Markus Reichstein, Miguel D. Mahecha

The R Journal

“Dimensionality reduction” (DR) is a widely used approach to find low dimensional and interpretable representations of data that are natively embedded in high-dimensional spaces. DR ca nbe realized by a plethora of methods with different properties, objectives, and, hence, (dis)advantages. The resulting low-dimensional data embeddings are often difficult to compare with objective criteria. Here, we introduce the dimRed and coRanking packages for the R language. These open source software packages enable users to easily access multiple classical and advanced DR methods using a common interface. The packages also provide quality indicators for the embeddings and easy visualization of high dimensional …


Collections In R: Review And Proposal, Timothy Barry Jul 2018

Collections In R: Review And Proposal, Timothy Barry

The R Journal

R is a powerful tool for data processing, visualization, and modeling. However, R is slower than other languages used for similar purposes, such as Python. One reason for this is that R lacks base support for collections, abstract data types that store, manipulate, and return data (e.g., sets, maps, stacks). An exciting recent trend in the R extension ecosystem is the development of collection packages, packages that provide classes that implement common collections. At least 12 collection packages are available across the two major R extension repositories, the Comprehensive R Archive Network (CRAN) and Bioconductor. In this article, we compare …


Pstat: An R Package To Assess Population Differentiation In Phenotypic Traits, Stéphane Blondeau Da Silva, Anne Da Silva Jul 2018

Pstat: An R Package To Assess Population Differentiation In Phenotypic Traits, Stéphane Blondeau Da Silva, Anne Da Silva

The R Journal

The package Pstat calculates PST values to assess differentiation among populations from a set of quantitative traits and provides bootstrapped distributions and confidence intervals for PST. Variations of PST as a function of the parameter c/h2 are studied as well. The package implements different transformations of the measured phenotypic traits to eliminate variation resulting from allometric growth, including calculation of residuals from linear regression, Reist standardization, and the Aitchison transformation.


Residuals And Diagnostics For Binary And Ordinal Regression Models: An Introduction To The Sure Package, Brandon M. Greenwell, Andrew J. Mccarthy, Bradley C. Boehmke, Dungang Liu Jul 2018

Residuals And Diagnostics For Binary And Ordinal Regression Models: An Introduction To The Sure Package, Brandon M. Greenwell, Andrew J. Mccarthy, Bradley C. Boehmke, Dungang Liu

The R Journal

Residual diagnostics is an important topic in the classroom, but it is less often used in practice when the response is binary or ordinal. Part of the reason for this is that generalized models for discrete data, like cumulative link models and logistic regression, do not produce standard residuals that are easily interpreted as those in ordinary linear regression. In this paper, we introduce the R package sure, which implements a recently developed idea of SUrrogate REsiduals. We demonstrate the utility of the package in detection of cumulative link model misspecification with respect to mean structures, link functions, …


Hrm: An R Package For Analysing High-Dimensional Multi-Factor Repeated Measures Authors: Martin Happ, Solomon W. Harrar And Arne C. Bathke, Martin Happ, Solomon W. Harrar, Arne C. Bathke Jul 2018

Hrm: An R Package For Analysing High-Dimensional Multi-Factor Repeated Measures Authors: Martin Happ, Solomon W. Harrar And Arne C. Bathke, Martin Happ, Solomon W. Harrar, Arne C. Bathke

The R Journal

High-dimensional longitudinal data pose a serious challenge for statistical inference as many test statistics cannot be computed for high-dimensional data, or they do not maintain the nominal type-I error rate, or have very low power. Therefore, it is necessary to derive new inference methods capable of dealing with high dimensionality, and to make them available to statistics practitioners. One such method is implemented in the package HRM described in this article. This new method uses a similar approach as the Welch-Satterthwaite t-test approximation and works very well for high-dimensional data as long as the data distribution is not too skewed …


R Foundation News, Torsten Hothorn Jul 2018

R Foundation News, Torsten Hothorn

The R Journal

Donations and members

Donations

Supporting benefactors

Supporting institutions

Supporting members


Inventorymodel: An R Package For Centralized Inventory Problems, Alejandro Saavedra-Nieves Jul 2018

Inventorymodel: An R Package For Centralized Inventory Problems, Alejandro Saavedra-Nieves

The R Journal

Inventory management of goods is an integral part of logistics systems; common to various economic sectors such as industry, agriculture and trade; and independent of production volume. In general, as companies seek to minimize economic losses, studies on problems of multi-agent inventory have increased in recent years. A multi-agent inventory problem is a situation in which several agents face individual inventory problems and agree to coordinate their orders with the objective of reducing their costs. The R package Inventorymodel allows the determination of both the optimal policy for some inventory situations with deterministic demands and the allocation of costs from …


Rpostgis: Linking R With A Postgis Spatial Database, David Bucklin, Mathieu Basille Jul 2018

Rpostgis: Linking R With A Postgis Spatial Database, David Bucklin, Mathieu Basille

The R Journal

With the proliferation of sensors and the ease of data collection from online sources, large datasets have become the norm in many scientific disciplines, and efficient data storage, management, and retrival is imperative for large research projects. Relational databases provide a solution, but in order to be useful, must be able to be linked to analysis and visualization tools, such as R. Here, we present a package intended to facilitate integration of R with the open-source database software PostgreSQL, with a focus on its spatial extension, PostGIS. The package rpostgis (version 1.4.1) provides methods for spatial data handling (vector and …


R Package Imputetestbench To Compare Imputation Methods For Univariate Time Series, Marcus W. Beck, Neeraj Bokde, Gualberto Asencio-Cortés, Kishore Kulat Jul 2018

R Package Imputetestbench To Compare Imputation Methods For Univariate Time Series, Marcus W. Beck, Neeraj Bokde, Gualberto Asencio-Cortés, Kishore Kulat

The R Journal

Missing observations are common in time series data and several methods are available to impute these values prior to analysis. Variation in statistical characteristics of univariate time series can have a profound effect on characteristics of missing observations and, therefore, the accuracy of different imputation methods. The imputeTestbench package can be used to compare the prediction accuracy of different methods as related to the amount and type of missing data for a user-supplied dataset. Missing data are simulated by removing observations completely at random or in blocks of different sizes depending on characteristics of the data. Several imputation algorithms are …


Advanced Bayesian Multilevel Modeling With The R Package Brms, Paul-Christian Bürkner Jul 2018

Advanced Bayesian Multilevel Modeling With The R Package Brms, Paul-Christian Bürkner

The R Journal

The brms package allows R users to easily specify a wide range of Bayesian single-level and multilevel models which are fit with the probabilistic programming language Stan behind the scenes. Several response distributions are supported, of which all parameters (e.g., location, scale, and shape) can be predicted. Non-linear relationships may be specified using non-linear predictor terms or semi-parametric approaches such as splines or Gaussian processes. Multivariate models can be fit as well. To make all of these modeling options possible in a multilevel framework, brms provides an intuitive and powerful formula syntax, which extends the well known formula syntax of …


Welfare, Inequality And Poverty Analysis With Rtip: An Approach Based On Stochastic Dominance, Angel Berihuete, Carmen D. Ramos, Miguel A. Sordo Jul 2018

Welfare, Inequality And Poverty Analysis With Rtip: An Approach Based On Stochastic Dominance, Angel Berihuete, Carmen D. Ramos, Miguel A. Sordo

The R Journal

Disparities in economic welfare, inequality and poverty across and within countries are of great interest to sociologists, economists, researchers, social organizations and political scientists. Information about these topics is commonly based on surveys. We present a package called rtip that implements techniques based on stochastic dominance to make unambiguous comparisons, in terms of welfare, poverty and inequality, among income distributions. Besides providing point estimates and confidence intervals for the most commonly used indicators of these characteristics, the package rtip estimates the usual Lorenz curve, the generalized Lorenz curve, the TIP (Three I’s of Poverty) curve and allows to test statistically …


Support Vector Machines For Survival Analysis With R, Césaire J.K. Fouodo, Inke R. König, Claus Weihs, Andreas Ziegler, Marvin N. Wright Jul 2018

Support Vector Machines For Survival Analysis With R, Césaire J.K. Fouodo, Inke R. König, Claus Weihs, Andreas Ziegler, Marvin N. Wright

The R Journal

This article introduces the R package survivalsvm, implementing support vector machines for survival analysis. Three approaches are available in the package: The regression approach takes censoring into account when formulating the inequality constraints of the support vector problem. In the ranking approach, the inequality constraints set the objective to maximize the concordance index for comparable pairs of observations. The hybrid approach combines the regression and ranking constraints in a single model. We describe survival support vector machines and their implementation, provide examples and compare the prediction performance with the Cox proportional hazards model, random survival forests and gradient boosting using …


Mglm: An R Package For Multivariate Categorical Data Analysis, Juhyun Kim, Yiwen Zhang, Joshua Day, Hua Zhou Jul 2018

Mglm: An R Package For Multivariate Categorical Data Analysis, Juhyun Kim, Yiwen Zhang, Joshua Day, Hua Zhou

The R Journal

Data with multiple responses is ubiquitous in modern applications. However, few tools are available for regression analysis of multivariate counts. The most popular multinomial-logit model has a very restrictive mean-variance structure, limiting its applicability to many data sets. This article introduces an R package MGLM, short for multivariate response generalized linear models, that expands the current tools for regression analysis of polytomous data. Distribution fitting, random number generation, regression, and sparse regression are treated in a unifying framework. The algorithm, usage, and implementation details are discussed.


Cchs: An R Package For Stratified Case-Cohort Studies, Edmund Jones Jul 2018

Cchs: An R Package For Stratified Case-Cohort Studies, Edmund Jones

The R Journal

The cchs package contains a function, also called cchs, for analyzing data from a stratified case-cohort study, as used in epidemiology. For data from this type of study, cchs calculates Estimator III of Borgan et al. (2000), which is a score-unbiased estimator for the regression coefficients in the Cox proportional hazards model. From the user’s point of view, the function is similar to coxph (in the survival package) and other widely used model-fitting functions. Convenient software has not previously been available for Estimator III since it is complicated to calculate. SAS and S-Plus code-fragments for the calculation have been published, …


Small Area Disease Risk Estimation And Visualization Using R, Paula Moraga Jul 2018

Small Area Disease Risk Estimation And Visualization Using R, Paula Moraga

The R Journal

Small area disease risk estimation is essential for disease prevention and control. In this paper, we demonstrate how R can be used to obtain disease risk estimates and quantify risk factors using areal data. We explain how to define disease risk models and how to perform Bayesian inference using the INLA package. We also show how to make interactive maps of estimates using the leaflet package to better understand the disease spatial patterns and communicate the results. We show an example of lung cancer risk in Pennsylvania, United States, in year 2002, and demonstrate that R represents an excellent tool …


Semiparametric Generalized Linear Models With The Gldrm Package, Michael J. Wurm, Paul J. Rathouz Jul 2018

Semiparametric Generalized Linear Models With The Gldrm Package, Michael J. Wurm, Paul J. Rathouz

The R Journal

This paper introduces a new algorithm to estimate and perform inferences on a recently proposed and developed semiparametric generalized linear model (glm). Rather than selecting a particular parametric exponential family model, such as the Poisson distribution, this semiparametric glm assumes that the response is drawn from the more general exponential tilt family. The regression coefficients and unspecified reference distribution are estimated by maximizing a semiparametric likelihood. The new algorithm incorporates several computational stability and efficiency improvements over the algorithm originally proposed. In particular, the new algorithm performs well for either small or large support for the nonparametric response distribution. The …


Ratingscalereduction Package: Stepwise Rating Scale Item Reduction Without Predictability Loss, Waldemar W. Koczkodaj, Feng Li, Alicja Wolny–Dominiak Jul 2018

Ratingscalereduction Package: Stepwise Rating Scale Item Reduction Without Predictability Loss, Waldemar W. Koczkodaj, Feng Li, Alicja Wolny–Dominiak

The R Journal

This study presents an innovative method for reducing the number of rating scale items without predictability loss. The “area under the receiver operator curve” method (AUC ROC) is used for the stepwise method of reducing items of a rating scale. RatingScaleReduction R package contains the presented implementation. Differential evolution (a metaheuristic for optimization) was applied to one of the analyzed datasets to illustrate that the presented stepwise method can be used with other classifiers to reduce the number of rating scale items (variables). The targeted areas of application are decision making, data mining, machine learning, and psychometrics.


News From The Bioconductor Project, Bioconductor Core Team Jul 2018

News From The Bioconductor Project, Bioconductor Core Team

The R Journal

The Bioconductor project provides tools for the analysis and comprehension of high-throughput genomic data. Bioconductor 3.7 was released on 1 May, 2018. It is compatible with R 3.5.1 and consists of 1560 software packages, 342 experiment data packages, and 919 up-to-date annotation packages. The release announcement includes descriptions of 98 new software packages and updated NEWS files for many additional packages. Start using Bioconductor by installing the most recent version of R and evaluating the commands


A System For An Accountable Data Analysis Process In R, Jonathan Gelfond, Martin Goros, Brian Hernandez, Alex Bokov Jul 2018

A System For An Accountable Data Analysis Process In R, Jonathan Gelfond, Martin Goros, Brian Hernandez, Alex Bokov

The R Journal

Efficiently producing transparent analyses may be difficult for beginners or tedious for the experienced. This implies a need for computing systems and environments that can efficiently satisfy reproducibility and accountability standards. To this end, we have developed a system, R package, and R Shiny application called adapr (Accountable Data Analysis Process in R) that is built on the principle of accountable units. An accountable unit is a data file (statistic, table or graphic) that can be associated with a provenance, meaning how it was created, when it was created and who created it, and this is similar to the ’verifiable …


Mmpf: Monte-Carlo Methods For Prediction Functions, Zachary M. Jones Jul 2018

Mmpf: Monte-Carlo Methods For Prediction Functions, Zachary M. Jones

The R Journal

Machine learning methods can often learn high-dimensional functions which generalize well but are not human interpretable. The mmpf package marginalizes prediction functions using Monte-Carlo methods, allowing users to investigate the behavior of these learned functions, as on a lower dimensional subset of input features: partial dependence and variations thereof. This makes machine learning methods more useful in situations where accurate prediction is not the only goal, such as in the social sciences where linear models are commonly used because of their interpretability.

Many methods for estimating prediction functions produce estimated functions which are not directly human-interpretable because of their complexity: …


Generalized Additive Model Multiple Imputation By Chained Equations With Package Imputerobust, Daniel Salfran, Martin Spiess Jul 2018

Generalized Additive Model Multiple Imputation By Chained Equations With Package Imputerobust, Daniel Salfran, Martin Spiess

The R Journal

Data analysis, common to all empirical sciences, often requires complete data sets. Unfortunately, real world data collection will usually result in data values not being observed. We present a package for robust multiple imputation (the ImputeRobust package) that allows the use of generalized additive models for location, scale, and shape in the context of chained equations. The paper describes the basics of the imputation technique which builds on a semi-parametric regression model (GAMLSS) and the algorithms and functions provided with the corresponding package. Furthermore, some illustrative examples are provided.


Fhdi: An R Package For Fractional Hot Deck Imputation, Jongho Im, In Ho Cho, Jae Kwang Kim Jul 2018

Fhdi: An R Package For Fractional Hot Deck Imputation, Jongho Im, In Ho Cho, Jae Kwang Kim

The R Journal

Fractional hot deck imputation (FHDI), proposed by Kalton and Kish (1984) and investigated by Kim and Fuller (2004), is a tool for handling item nonresponse in survey sampling. In FHDI, each missing item is filled with multiple observed values yielding a single completed data set for subsequent analyses. An R package FHDI is developed to perform FHDI and also the fully efficient fractional imputation (FEFI) method of (Fuller and Kim, 2005) to impute multivariate missing data with arbitrary missing patterns. FHDI substitutes missing items with a few observed values jointly obtained from a set of donors whereas the FEFI uses …