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Conversations in Time: Interactive Visualization to Explore Structured Temporal Data 时间中的对话:探索结构化时间数据的交互式可视化
Pub Date : 2021-01-01 DOI: 10.32614/rj-2021-050
Earo Wang, D. Cook
Temporal data often has a hierarchical structure, defined by categorical variables describing different levels, such as political regions or sales products. Nesting of categorical variables produces a hierarchical structure. The tsibbletalk package is developed to allow a user to interactively explore temporal data, relative to the nested or crossed structures. It can help to discover differences between category levels, and uncover interesting periodic or aperiodic slices. The package implements a shared tsibble object that allows for linked brushing between coordinated views, and a shiny module that aids in wrapping time lines for seasonal patterns. The tools are demonstrated using two data examples: domestic tourism in Australia and pedestrian traffic in Melbourne.
时间数据通常具有层次结构,由描述不同层次的分类变量定义,例如政治区域或销售产品。分类变量的嵌套产生层次结构。开发tabletalk包是为了允许用户交互地探索相对于嵌套结构或交叉结构的时态数据。它可以帮助发现类别级别之间的差异,并发现有趣的周期性或非周期性切片。这个包实现了一个共享表对象,它允许在协调视图之间链接刷表,还有一个闪亮的模块,它帮助包装季节模式的时间线。使用两个数据示例演示了这些工具:澳大利亚的国内旅游和墨尔本的行人交通。
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引用次数: 0
tramME: Mixed-Effects Transformation Models Using Template Model Builder 使用模板模型生成器的混合效果转换模型
Pub Date : 2021-01-01 DOI: 10.32614/rj-2021-075
Bálint Tamási, T. Hothorn
Linear transformation models constitute a general family of parametric regression models for discrete and continuous responses. To accommodate correlated responses, the model is extended by incorporating mixed effects. This article presents the R package tramME , which builds on existing implementations of transformation models ( mlt and tram packages) as well as Laplace approximation and automatic differentiation (using the TMB package), to calculate estimates and perform likelihood inference in mixed-effects transformation models. The resulting framework can be readily applied to a wide range of regression problems with grouped data structures.
线性变换模型构成了离散和连续响应的参数回归模型的一般族。为了适应相关的响应,该模型通过纳入混合效应进行扩展。本文介绍了R包tramME,它建立在现有的转换模型实现(mlt和tram包)以及拉普拉斯近似和自动微分(使用TMB包)的基础上,在混合效果转换模型中计算估计并执行似然推断。由此产生的框架可以很容易地应用于具有分组数据结构的各种回归问题。
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引用次数: 14
The R Developer Community Does Have a Strong Software Engineering Culture R开发人员社区确实有很强的软件工程文化
Pub Date : 2021-01-01 DOI: 10.32614/rj-2021-110
M. Salmon, Karthik Ram
There is a strong software engineering culture in the R developer community. We recommend creating, updating and vetting packages as well as keeping up with community standards. We invite contributions to the rOpenSci project, where participants can gain experience that will shape their work and that of their peers.
在R开发人员社区中有很强的软件工程文化。我们建议创建、更新和审查软件包,并与社区标准保持一致。我们邀请对rOpenSci项目的贡献,参与者可以获得将影响他们和同行工作的经验。
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引用次数: 0
penPHcure: Variable Selection in Proportional Hazards Cure Model with Time-Varying Covariates 具有时变协变量的比例风险治愈模型的变量选择
Pub Date : 2021-01-01 DOI: 10.32614/rj-2021-061
Alessandro Beretta, C. Heuchenne
We describe the penPHcure R package, which implements the semi-parametric proportionalhazards (PH) cure model of Sy and Taylor (2000) extended to time-varying covariates and the variable selection technique based on its SCAD-penalized likelihood proposed by Beretta and Heuchenne (2019a). In survival analysis, cure models are a useful tool when a fraction of the population is likely to be immune from the event of interest. They can separate the effects of certain factors on the probability to be susceptible and on the time until the occurrence of the event. Moreover, the penPHcure package allows the user to simulate data from a PH cure model, where the event-times are generated on a continuous scale from a piecewise exponential distribution conditional on time-varying covariates, with a method similar to Hendry (2014). We present the results of a simulation study to assess the finite sample performance of the methodology and we illustrate the functionalities of the penPHcure package using criminal recidivism data.
我们描述了penPHcure R包,它实现了Sy和Taylor(2000)的半参数比例风险(PH)治愈模型扩展到时变协变量,以及基于Beretta和Heuchenne (2019a)提出的scad惩罚似然的变量选择技术。在生存分析中,当一小部分人群可能对感兴趣的事件免疫时,治愈模型是一个有用的工具。他们可以将某些因素对易感概率的影响和对事件发生前时间的影响分开。此外,penPHcure包允许用户模拟PH固化模型中的数据,其中事件时间是由时变协变量条件下的分段指数分布在连续尺度上生成的,方法类似于Hendry(2014)。我们提出了一项模拟研究的结果,以评估该方法的有限样本性能,并使用犯罪累犯数据说明penPHcure包的功能。
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引用次数: 3
Software Engineering and R Programming: A Call for Research 软件工程和R编程:一个研究呼吁
Pub Date : 2021-01-01 DOI: 10.32614/rj-2021-108
M. Vidoni
Although R programming has been a part of research since its origins in the 1990s, few studies address scientific software development from a Software Engineering (SE) perspective. The past few years have seen unparalleled growth in the R community, and it is time to push the boundaries of SE research and R programming forwards. This paper discusses relevant studies that close this gap Additionally, it proposes a set of good practices derived from those findings aiming to act as a call-to-arms for both the R and RSE (Research SE) community to explore specific, interdisciplinary paths of research.
尽管R编程自20世纪90年代以来一直是研究的一部分,但很少有研究从软件工程(SE)的角度来解决科学的软件开发。在过去的几年里,R社区取得了前所未有的发展,现在是时候推动SE研究和R编程向前发展了。本文讨论了缩小这一差距的相关研究。此外,本文还提出了一套源自这些研究结果的良好实践,旨在为R和RSE(研究SE)社区探索具体的跨学科研究路径提供帮助。
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引用次数: 3
Analysis of Corneal Data in R with the rPACI Package rPACI包在R中的角膜数据分析
Pub Date : 2021-01-01 DOI: 10.32614/rj-2021-099
D. Ramos-López, A. D. Maldonado
In ophthalmology, the early detection of keratoconus is still a crucial problem. Placido disk corneal topographers are an essential tool in clinical practice, and many indices for diagnosing corneal irregularities exist. The main goal of this work is to present the R package rPACI , providing several functions to handle and analyze corneal data. This package implements primary indices of corneal irregularity (based on geometrical properties) and compound indices built from the primary ones, either using a generalized linear model, or as a Bayesian classifier using a hybrid Bayesian network and performing approximate inference. rPACI aims to make the analysis of corneal data accessible for practitioners and researchers in the field. Moreover, a shiny app was developed so that rPACI can be used in any web browser, in a truly user-friendly graphical interface, without installing R or writing any R code. It is openly deployed at https://admaldonado.shinyapps.io/rPACI/ .
本工作的主要目标是提出R包rPACI,提供几个功能来处理和分析角膜数据。该包实现了角膜不规则性的主要指标(基于几何属性)和从主要指标构建的复合指标,要么使用广义线性模型,要么使用混合贝叶斯网络作为贝叶斯分类器并执行近似推理。
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引用次数: 0
exPrior: An R Package for the Formulation of Ex-Situ Priors exPrior:一个R包,用于制定非原位先验
Pub Date : 2021-01-01 DOI: 10.32614/rj-2021-031
F. Heße, K. Cucchi, Nura Kawa, Y. Rubin
The exPrior package implements a procedure for formulating informative priors of geostatistical properties for a target field site, called ex-situ priors and introduced in ?. The procedure uses a Bayesian hierarchical model to assimilate multiple types of data coming from multiple sites considered as similar to the target site. This prior summarizes the information contained in the data in the form of a probability density function that can be used to better inform further geostatistical investigations at the site. The formulation of the prior uses ex-situ data; where the data set can either be gathered by the user or come in the form of a structured database. The package is designed to be flexible to that regard. For illustration purposes and for easiness of use, the package is ready to be used with the worldwide hydrogeological parameter database (WWHYPDA) ?.
exPrior软件包实现了一个程序,用于为目标现场制定地质统计属性的信息先验,称为非原位先验,并在?该过程使用贝叶斯分层模型来吸收来自被认为与目标站点相似的多个站点的多种类型的数据。该先验以概率密度函数的形式总结了数据中包含的信息,可用于更好地为现场的进一步地质统计调查提供信息。先前的公式使用非原位数据;数据集可以由用户收集,也可以以结构化数据库的形式出现。在这方面,一揽子计划的设计是灵活的。为了说明目的和易于使用,该软件包已准备好与全球水文地质参数数据库(WWHYPDA)一起使用。
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引用次数: 3
spfilteR: An R package for Semiparametric Spatial Filtering with Eigenvectors in (Generalized) Linear Models spfilteR:一个用于(广义)线性模型中特征向量的半参数空间滤波的R包
Pub Date : 2021-01-01 DOI: 10.32614/rj-2021-085
Sebastian Juhl
Eigenvector-based spatial filtering constitutes a highly flexible semiparametric approach to account for spatial autocorrelation in a regression framework. It combines judiciously selected eigenvectors from a transformed connectivity matrix to construct a synthetic spatial filter and remove spatial patterns from model residuals. This article introduces the spfilteR package that provides several useful and flexible tools to estimate spatially filtered linear and generalized linear models in R. While the package features functions to identify relevant eigenvectors based on different selection criteria in an unsupervised fashion, it also helps users to perform supervised spatial filtering and to select eigenvectors based on alternative user-defined criteria. After a brief discussion of the eigenvectorbased spatial filtering approach, this article presents the main functions of the package and illustrates their usage. A comparison to alternative implementations in other R packages highlights the added value of the spfilteR package.
基于特征向量的空间滤波构成了一种高度灵活的半参数方法来解释回归框架中的空间自相关。它结合从转换的连通性矩阵中明智地选择特征向量来构建一个合成空间滤波器,并从模型残差中去除空间模式。本文介绍了spfilteR包,它提供了几个有用和灵活的工具来估计r中的空间过滤线性和广义线性模型。虽然该包的功能以无监督的方式基于不同的选择标准识别相关的特征向量,但它还帮助用户执行监督空间过滤并根据其他用户定义的标准选择特征向量。在简要讨论了基于特征向量的空间滤波方法之后,本文介绍了该包的主要功能并说明了它们的使用方法。与其他R包中的替代实现的比较突出了spfilteR包的附加价值。
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引用次数: 1
bcmixed: A Package for Median Inference on Longitudinal Data with the Box-Cox Transformation 基于Box-Cox变换的纵向数据中值推断包
Pub Date : 2021-01-01 DOI: 10.32614/rj-2021-083
K. Maruo, Ryota Ishii, Y. Yamaguchi, M. Gosho
This article illustrates the use of the bcmixed package and focuses on the two main functions: bcmarg and bcmmrm. The bcmarg function provides inference results for a marginal model of a mixed effect model using the Box–Cox transformation. The bcmmrm function provides model median inferences based on the mixed effect models for repeated measures analysis using the Box–Cox transformation for longitudinal randomized clinical trials. Using the bcmmrm function, analysis results with high power and high interpretability for treatment effects can be obtained for longitudinal randomized clinical trials with skewed outcomes. Further, the bcmixed package provides summarizing and visualization tools, which would be helpful to write clinical trial reports. Introduction Longitudinal data are often observed in medical or biological research. One of the most popular statistical models for studying longitudinal continuous outcomes is the linear mixed effect model. Several packages are available from CRAN that allow for the implementation of linear mixed effects models (e.g., nlme (Pinheiro et al., 2019), glme (Sam Weerahandi et al., 2021), lme4 (Bates et al., 2015), CLME (Jelsema and Peddada, 2016), PLmixed (Rockwood and Jeon, 2019), MCMCglmm (Hadfield, 2010)).The linear mixed effect models assume that longitudinal outcomes follow multivariate normal distribution. However, the distribution of the outcome is often right skewed in the medical and biological fields. Therefore, evaluating fixed effects based on the normal distribution theory may result in inefficient inferences such as power loss for some statistical tests. In addition, although a model-based mean for a certain level of the categorical exploratory variables is often estimated when applying the linear mixed effect model (e.g., the model-based mean for each treatment group of a last visit in a randomized clinical trial), the mean may be inadequate as a representative value for the skewed data. The Box–Cox transformation (Box and Cox, 1964) is often applied to skewed longitudinal data (Lipsitz et al., 2000) to reduce the skewness of a skewed outcome and apply existing statistical models based on a normal distribution. However, it is difficult to directly interpret the model mean estimated on the scale after applying some transformations to the outcome variable. For the sake of the interpretability of the analysis results, Maruo et al. (2015) propose a model median inference method on the original scale based on the Box–Cox transformation in the context of randomized clinical trials. Maruo et al. (2017) extend this method to the framework of mixed effects models for repeated measures (MMRM) analysis (Mallinckrodt et al., 2001) in the context of longitudinal randomized clinical trials. The bcmixed package (Maruo et al., 2020) contains functions to estimate model medians for longitudinal data proposed by Maruo et al. (2017) as well as a sample data set that is used in Maruo et al. (2017). In this package
在本文中,我们考虑了研究人员对随机效应不感兴趣而对评估固定效应感兴趣的情况。在这种情况下,可以实现线性混合效应模型(1)的简单公式,其中随机效应不显式建模,而是作为协方差矩阵Vi的一部分。我们关注这样一个“边际”平均模型。对于ni = T(即没有缺失值的受试者),V = Vi中的协方差参数向量记为α = (α1,…)。, αm)。α的维数m取决于T和指定的协方差结构。设模型参数向量为θ = (λ, βT, αT)T。θ的最大似然估计是通过最大化λ的剖面似然得到的(Lipsitz et al., 2000;Maruo et al., 2017)。最大似然估计量θ的基于模型和鲁棒方差估计量分别由V θ ={−Ĥ} - 1和V θ ={−Ĥ} - 1 Ĵ{−Ĥ} - 1给出,其中H =∂2∂θ∂θT l(θ), J =∑n i=1{∂∂θ li(θ)}T, l(θ)是n个受试者的似然函数,li(θ)是第i个受试者的似然函数。矩阵Ĥ和Ĵ分别由矩阵H和J由θ替换为θ³得到。稳健方差估计量是一个渐近有效的估计量,即使模型(1)是错误指定的(Cox, 1961)。我们现在关注某种疾病的持续和积极的结果,并考虑一些治疗的疗效(组指数:g = 1,…)固定效应参数向量由β = (β I, βg, β T, β T gt, β T c) T给出,其中β I, βg = (βg(1),…, βg(G−1))T, βt = (βt(1),…, βt(T−1))T, βgt = (βgt(1,1), βgt(1,2),…, βgt(G−1,T−1))T, βc = (βc(1),…, βc(C)) T分别为截距、组、场合、逐场合和协变量参数向量。虽然G组和场合T设为参考水平,但为了便于描述,我们设βg(G) = βt(T) = βgt(G, T) = βgt(G, T) = 0 (G = 1,…), G, t = 1,…在这些设置下,初始尺度上处理组g在T时刻的模型中位数ξ(g, T)由ξ(g, T) = {λ (β I + βg(g) + β T (T) + βgt(g, T) + x T c′βc) + 1}1/λ给出,其中xc′是所有受试者每个协变量的均值向量。模型中值是模型均值在Box-Cox变换尺度上的Box-Cox逆变换。模型中位数很容易解释,因为它是原始尺度上中位数的估计量。使用delta方法,模型中位数的极大似然估计量ξ²(g,t)的方差估计量由V(·)ξ(g,t) =∆t ξ(g,t)V(·)θ∆ξ(g,t)给出,其中∆ξ(g,t) =∂∂θ ξ(g,t)∣∣∣θ=θ。如果我们使用V(·)θ = V(M) θ,我们得到基于模型的方差估计量V(M) ξ(g,t)。另一方面,当我们使用V(·)θ = V (R) θ时,得到了稳健的方差估计量V xi(g,t)。因此,g1组和g2组在t时刻的模型中位数差由δ(g1;g2,t) = ξ(g1,t) - ξ(g2,t)给出,模型中位数差的最大似然估计量δ(g1;g2,t)的方差估计量由Vδ(g1;g2,t) =(∆(g1,t) -∆(g2,t)) TV(·)θ(∆(g1,t) -∆(g2,t))给出。采用与模型中值估计相同的方法获得基于模型的稳健方差估计量。利用极大似然估计量的渐近正态性,得到δ(g1;g2,t)的100(1−α)%置信区间为δ(g1;g2,t)±Φ−1(1−α/2)√V(·)δ(g1;g2,t),其中Φ−1(·)为标准正态分布的分位数函数。对原假设δ(g1;g2,t) = 0进行wald型检验,检验统计量t = δ δ(g1;g2,t) /√V(·)δ(g1;g2,t)。对于小样本,上述推理过程的性能可能较低,因为它们是基于最大似然估计的渐近性质。因此,Maruo et al.(2017)参考Schluchter and Elashoff(1990)的研究,对模型中位数差异的推论采用了以下经验小样本调整。他们为复合对称(CS)或一阶自回归(AR(1))结构的中位数差提供调整后的标准误差(SE)为√M/(M−p)V(·)δ(g1;g2,t),非结构化(UN)结构为√n∗/(n∗−t) ×√V(·)δ(g1;g2,t)。
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引用次数: 1
Rejoinder: Software Engineering and R Programming 答辩:软件工程和R编程
Pub Date : 2021-01-01 DOI: 10.32614/rj-2021-112
M. Vidoni
It is a pleasure to take part in such fruitful discussion about the relationship between Software Engineering and R programming, and what could be gain by allowing each to look more closely at the other. Several discussants make valuable arguments that ought to be further discussed.
很高兴能参加这样富有成效的讨论,讨论软件工程和R编程之间的关系,以及允许彼此更密切地观察对方可以获得什么。几位讨论者提出了值得进一步讨论的有价值的论点。
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引用次数: 0
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