Background: Ternary plots can effectively display compositional data and help to understand its multidimensional patterns. However, they are currently greatly underused in demography. Objective: My goal is to develop an interactive web-based visualization of compositional data on international migration flows in order to compare its developments over time and across countries, and through this example demonstrate the utility of ternary diagrams. Methods: R Shiny framework is used to build a web application. Immigration and emigration flows in the EU Member States from 1998 to 2015 are grouped into three conventional categories (nationals of a reporting country, [other] EU nationals, and non-EU nationals) and presented on ternary diagrams. Results: Compositional data on migration flows can be effectively visualized using ternary plots. An interactive web application has been developed that allows comparative exploratory analysis of immigration and emigration composition and size in the EU countries over time. The impact of the entry of new countries to the EU can be assessed by comparing data referring to the EU composition of 28 Member States with data referring to the EU composition of the reference period. Conclusions: Ternary plots can facilitate compositional analysis of migration flows grouped into three categories. Contribution: I introduce ternary plots for an exploratory analysis of migration composition and provide an online tool to carry out illustrative exploration. Demographic analysis of compositional data can benefit from the wider use of such plots.

中文翻译：

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1998-2015年间探索欧盟国家国际移民流动构成的可视化工具

背景：三元图可以有效地显示成分数据并帮助理解其多维模式。但是，它们目前在人口统计学中的使用率很低。目标：我的目标是开发基于网络的交互式国际迁移流量构成数据的可视化，以比较其随时间推移以及各个国家之间的发展情况，并通过该示例演示三元图的实用性。方法：R Shiny框架用于构建Web应用程序。从1998年到2015年，欧盟成员国的移民流量分为三个常规类别（报告国国民，[其他]欧盟国民和非欧盟国民），并以三元图表示。结果：使用三元图可以有效地可视化迁移流的组成数据。已经开发了一个交互式Web应用程序，该应用程序可以对欧盟国家随时间推移的移民及其构成和规模进行比较性探索性分析。新国家加入欧盟的影响可以通过将涉及28个成员国的欧盟组成的数据与涉及参考时期欧盟组成的数据进行比较来评估。结论：三元图可以方便地对迁移流分为三类进行成分分析。贡献：我介绍了三元图以对迁移构成进行探索性分析，并提供了进行说明性探索的在线工具。组成数据的人口统计分析可从此类图的更广泛使用中受益。