Programming Languages and Compilers Commons^™

Modeling Programming Language Trends Using Markov Processes, Cody Clymer, Adrian Alberto, Mike Merrill

Math 365 Class Projects

Which Languages Are Worth Investing In? One of the many issues in the computer science industry is knowing which technologies to invest in. Programming languages are a prime example of these technologies, so investors and innovators need to know which programming languages will grow in use over time so that new businesses can grow alongside them.

C++ Risk Simulation To Generate Ai, David Sky Nunez

A with Honors Projects

For this A with Honors project, the student set out to create a way to run thousands of simulations for the board game, RISK, supplying information for the game player to be able to make more strategic decisions when playing the game.

Partial Rank Data With The Hyper2 Package: Likelihood Functions For Generalized Bradley-Terry Models, Robin K. S Hankin

The R Journal

Here I present the hyper2 package for generalized Bradley-Terry models and give examples from two competitive situations: single scull rowing, and the competitive cooking game show Master Chef Australia. A number of natural statistical hypotheses may be tested straightforwardly using the software.

Simulating Probabilistic Long-Term Effects In Models With Temporal Dependence, Christopher Gandrud, Laron K. Williams

The R Journal

The R package pltesim calculates and depicts probabilistic long-term effects in binary models with temporal dependence variables. The package performs two tasks. First, it calculates the change in the probability of the event occurring given a change in a theoretical variable. Second, it calculates the rolling difference in the future probability of the event for two scenarios: one where the event occurred at a given time and one where the event does not occur. The package is consistent with the recent movement to depict meaningful and easy-to-interpret quantities of interest with the requisite measures of uncertainty. It is the first …

Splitting It Up: The Spduration Split-Population Duration Regression Package For Time-Varying Covariates, Andreas Beger, Daniel W. Hill Jr, Nils W. Metternich, Shahryar Minhas, Michael D. Ward

The R Journal

We present an implementation of split-population duration regression in the spduration (Beger et al., 2017) package for R that allows for time-varying covariates. The statistical model accounts for units that are immune to a certain outcome and are not part of the duration process the researcher is primarily interested in. We provide insights for when immune units exist, that can significantly increase the predictive performance compared to standard duration models. The package includes estimation and several post-estimation methods for split-population Weibull and log-logistic models. Weprovide an empirical application to data on military coups.

Glmmtmb Balances Speed And Flexibility Among Packages For Zero-Inflated Generalized Linear Mixed Modeling, Mollie E. Brooks, Kasper Kristensen, Koen J. Van Benthem, Arni Magnusson, Casper W. Berg, Anders Nielsen, Hans J. Skaug, Martin Mächler, Benjamin M. Bolker

The R Journal

Count data can be analyzed using generalized linear mixed models when observations are correlated in ways that require random effects. However, count data are often zero-inflated, containing more zeros than would be expected from the typical error distributions. We present a new package, glmmTMB, and compare it to other R packages that fit zero-inflated mixed models. The glmmTMB package fits many types of GLMMs and extensions, including models with continuously distributed responses, but here we focus on count responses. glmmTMB is faster than glmmADMB, MCMCglmm, and brms, and more flexible than INLA and mgcv for zero-inflated …

Simulating Noisy, Nonparametric, And Multivariate Discrete Patterns, Ruby Sharma, Sajal Kumar, Hua Zhong, Mingzhou Song

The R Journal

Requiring no analytical forms, nonparametric discrete patterns are flexible in representing complex relationships among random variables. This makes them increasingly useful for data-driven applications. However, there appears to be no software tools for simulating nonparametric discrete patterns, which prevents objective evaluation of statistical methods that discover discrete relationships from data. We present a simulator to generate nonparametric discrete functions as contingency tables. User can request strictly many-to-one functional patterns. The simulator can also produce contingency tables representing dependent non-functional and independent relationships. An option is provided to apply random noise to contingency tables. We demonstrate the utility of the simulator …

The R Journal (December 2017) 9(2): Complete Issue, The R Foundation

The R Journal

Editorial, Roger Bivand

Contributed Research Articles

anchoredDistr: A Package for the Bayesian Inversion of Geostatistical Parameters with Multi-type and Multi-scale Data, Heather Savoy, Falk Heße, and Yoram Rubin

dGAselID: An R Package for Selecting a Variable Number of Features in High Dimensional Data, Nicolae Teodor Melita and Stefan Holban

Allele Imputation and Haplotype Determination from Databases Composed of Nuclear Families, Nathan Medina-Rodríguez and Ángelo Santana

Visualization of Regression Models Using visreg, Patrick Breheny and Woodrow Burchett

fourierin: An R package to compute Fourier integrals, Guillermo Basulto-Elias, Alicia Carriquiry, Kris De Brabanter, and Daniel J. Nordman

Discrete Time Markov Chains with …

The Welchadf Package For Robust Hypothesis Testing In Unbalanced Multivariate Mixed Models With Heteroscedastic And Non-Normal Data, Pablo J. Villacorta

The R Journal

A new R package is presented for dealing with non-normality and variance heterogeneity of sample data when conducting hypothesis tests of main effects and interactions in mixed models. The proposal departs from an existing SAS program which implements Johansen’s general formulation of Welch-James’s statistic with approximate degrees of freedom, which makes it suitable for testing any linear hypothesis concerning cell means in univariate and multivariate mixed model designs when the data pose non-normality and non-homogeneous variance. Improved type I error rate control is obtained using bootstrapping for calculating an empirical critical value, whereas robustness against non-normality is achieved through trimmed …

Mle.Tools: An R Package For Maximum Likelihood Bias Correction, Josmar Mazucheli, André Felipe B. Menezes, Saralees Nadarajah

The R Journal

Recently, Mazucheli (2017) uploaded the package mle.tools to CRAN. It can be used for bias corrections of maximum likelihood estimates through the methodology proposed by Cox and Snell (1968). The main function of the package, coxsnell.bc(), computes the bias corrected maximum likelihood estimates. Although in general, the bias corrected estimators may be expected to have better sampling properties than the uncorrected estimators, analytical expressions from the formula proposed by Cox and Snell (1968) are either tedious or impossible to obtain. The purpose of this paper is twofolded: to introduce the mle.tools package, especially the coxsnell.bc() function; secondly, to compare, for …

Liureg: A Comprehensive R Package For The Liu Estimation Of Linear Regression Model With Collinear Regressors, Muhammad Imdadullah, Muhammad Aslam, Saima Altaf

The R Journal

The Liu regression estimator is now a commonly used alternative to the conventional ordinary least squares estimator that avoids the adverse effects in the situations when there exists a considerable degree of multicollinearity among the regressors. There are only a few software packages available for estimation of the Liu regression coefficients, though with limited methods to estimate the Liu biasing parameter without addressing testing procedures. Our liureg package can be used to estimate the Liu regression coefficients utilizing a range of different existing biasing parameters, to test these coefficients with more than 15 Liu related statistics, and to present different …

Anomalydetection: Implementation Of Augmented Network Log Anomaly Detection Procedures, Robert J. Gutierrez, Bradley C. Boehmke, Air Force Institute Of Technology, Cade M. Saie, Trevor J. Bihl

The R Journal

As the number of cyber-attacks continues to grow on a daily basis, so does the delay in threat detection. For instance, in 2015, the Office of Personnel Management discovered that approximately 21.5 million individual records of Federal employees and contractors had been stolen. On average, the time between an attack and its discovery is more than 200 days. In the case of the OPM breach, the attack had been going on for almost a year. Currently, cyber analysts inspect numerous potential incidents on a daily basis, but have neither the time nor the resources available to perform such a task. …

Carx: An R Package To Estimate Censored Autoregressive Time Series With Exogenous Covariates, Chao Wang, Kung-Sik Chan

The R Journal

We implement in the R package carx a novel and computationally efficient quasi-likelihood method for estimating a censored autoregressive model with exogenous covariates. The proposed quasi-likelihood method reduces to maximum likelihood estimation in absence of censoring. The carx package contains many useful functions for practical data analysis with censored stochastic regression, including functions for outlier detection, model diagnostics, and prediction with censored time series data. We illustrate the capabilities of the carx package with simulations and an elaborate real data analysis.

Manlymix: An R Package For Manly Mixture Modeling, Xuwen Zhu, Volodymyr Melnykov

The R Journal

Model-based clustering is a popular technique for grouping objects based on a finite mixture model. It has countless applications in different fields of study. The R package ManlyMix implements the Manly mixture model that allows modeling skewness within data groups and performs cluster analysis. ManlyMix is a powerful diagnostics tool that is capable of conducting investigation concerning the normality of variables upon fitting of a Manly forward or backward model. Theoretical foundations as well as description of functions are provided. All features of the package are illustrated with examples in great detail. The analysis of real-life datasets demonstrates the flexibility …

Adegraphics: An S4 Lattice-Based Package For The Representation Of Multivariate Data, Aurélie Siberchicot, Alice Julien-Laferrière, Anne-Béatrice Dufour, Jean Thioulouse, Stéphane Dray

The R Journal

The ade4 package provides tools for multivariate analyses. Whereas new statistical methods have been added regularly in the package since its first release in 2002, the graphical functions, that are used to display the main outputs of an analysis, have not benefited from such enhancements. In this context, the adegraphics package, available on CRAN since 2015, is a complete reimplementation of the ade4 graphical functionalities but with large improvements. The package uses the S4 object system (each graph is an object) and is based on the graphical framework provided by lattice and grid. We give a brief description of the …

Arulesviz: Interactive Visualization Of Association Rules With R, Michael Hahsler

The R Journal

Association rule mining is a popular data mining method to discover interesting relation ships between variables in large databases. An extensive toolbox is available in the R-extension package arules. However, mining association rules often results in a vast number of found rules, leaving the analyst with the task to go through a large set of rules to identify interesting ones. Sifting manually through extensive sets of rules is time-consuming and strenuous. Visualization and especially interactive visualization has a long history of making large amounts of data better accessible. The R-extension package arulesViz provides most popular visualization techniques for association …

Ider: Intrinsic Dimension Estimation With R, Hideitsu Hino

The R Journal

In many data analyses, the dimensionality of the observed data is high while its intrinsic dimension remains quite low. Estimating the intrinsic dimension of an observed dataset is an essential preliminary step for dimensionality reduction, manifold learning, and visualization. This paper introduces an R package, named ider, that implements eight intrinsic dimension estimation methods, including a recently proposed method based on a second-order expansion of a probability mass function and a generalized linear model. The usage of each function in the package is explained with datasets generated using a function that is also included in the package

Ctmcd: An R Package For Estimating The Parameters Of A Continuous-Time Markov Chain From Discrete-Time Data, Marius Pfeuffer

The R Journal

This article introduces the R package ctmcd, which provides an implementation of methods for the estimation of the parameters of a continuous-time Markov chain given that data are only available on a discrete-time basis. This data consists of partial observations of the state of the chain, which are made without error at discrete times, an issue also known as the embedding problem for Markovchains. The functions provided comprise matrix logarithm based approximations as described in Israel et al. (2001), as well as Kreinin and Sidelnikova (2001), an expectation-maximization algorithm and a Gibbs sampling approach, both introduced by Bladt and …

Discrete Time Markov Chains With R, Giorgio Alfredo Spedicato

The R Journal

The markovchain package aims to provide S4 classes and methods to easily handle Discrete Time Markov Chains (DTMCs), filling the gap with what is currently available in the CRAN repository. In this work, I provide an exhaustive description of the main functions included in the package, as well as hands-on examples.

Fourierin: An R Package To Compute Fourier Integrals, Guillermo Basulto-Elias, Alicia Carriquiry, Kris De Brabanter, Daniel J. Nordman

The R Journal

We present the R package fourierin (Basulto-Elias, 2017) for evaluating functions defined as Fourier-type integrals over a collection of argument values. The integrals are finitely supported with integrands involving continuous functions of one or two variables. As an important application, such Fourier integrals arise in so-called “inversion formulas”, where one seeks to evaluate a probability density at a series of points from a given characteristic function (or vice versa) through Fourier transforms. This paper intends to fill a gap in current R software, where tools for repeated evaluation of functions as Fourier integrals are not directly available. We implement two …