Use Gmisc package for:
- Building a flowchart: https://cran.r-project.org/web/packages/Gmisc/vignettes/Grid-based_flowcharts.html
- Drawing transition classes: https://cran.r-project.org/web/packages/Gmisc/vignettes/Transition-class.html
see also:
http://gforge.se/2020/08/easy-flowchart/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+G-forgeR+%28G-Forge+%C2%BB+R%29