funcharts: control charts for multivariate functional data in R

Modern statistical process monitoring (SPM) applications focus on profile monitoring, i.e., the monitoring of process quality characteristics that can be modeled as profiles, also known as functional data. Despite the large interest in the profile monitoring literature, there is still a lack of software to facilitate its practical application. This article introduces the <b>funcharts</b> R package that implements recent developments on the SPM of multivariate functional quality characteristics, possibly adjusted by the influence of additional variables, referred to as covariates. The package also implements the real-time version of all control charting procedures to monitor profiles partially observed up to an intermediate domain point. The package is illustrated both through its built-in data generator and a real-case study on the SPM of Ro-Pax ship CO₂ emissions during navigation, which is based on the ShipNavigation data set provided in the Supplementary Material.

现代统计过程监控（Statistical Process Monitoring, SPM）应用聚焦于轮廓监控，即对可建模为轮廓（亦称函数型数据）的过程质量特性开展监控。尽管轮廓监控领域的相关研究已受到广泛关注，但目前仍缺乏可助力其实际落地的软件工具。本文介绍了<b>funcharts</b> R语言包，该工具实现了针对多元函数型质量特性的统计过程监控最新研究成果，且支持通过额外变量（亦称协变量）的影响对监控结果进行校正。该包还实现了所有控制图表法的实时版本，可对仅在中间域点处完成部分观测的轮廓开展监控。本文通过内置数据生成器，以及一项基于补充材料中提供的ShipNavigation数据集、针对航行过程中滚装客船（Ro-Pax）二氧化碳排放的统计过程监控实例研究，对该包的使用方法进行了演示。