28.25 Adding a Flowchart

REVIEW LaTeX and R both support extensive capability for generating pictures. Here we use the (Soetaert 2020) package to draw a flow chart, something that is a common requirement in documentation. The simple example shows the process of converting a .Rnw file using knitr (Xie 2025) to a LaTeX file which can then be processed by pdflatex to generate the .pdf file. The result can be seen in Figure @ref(fig:knitr:knitr_diagram_flowchart).

# Load package from the local library into the R session.

library(diagram)

# Identify some names for the nodes of the flowchart.

names   <- c(".Rnw", ".tex", ".pdf")

# Set up the connectivity data.

connect <- c(0,       0,          0,
             "knitr", 0,          0,
             0,       "pdflatex", 0)

# Constract a connectivity matrix and plot the flowchart.

matrix(nrow=3, ncol=3, byrow=TRUE, data=connect) %>%
  plotmat(pos=c(1, 2), name=names, box.col="orange")
The knitr process to generate a pdf.

(#fig:knitr:knitr_diagram_flowchart)The knitr process to generate a pdf.

There are many more possibilities provided by diagram (Soetaert 2020) and if interested you can explore demo(plotmat) and demo(plotweb).

References

Soetaert, Karline. 2020. Diagram: Functions for Visualising Simple Graphs (Networks), Plotting Flow Diagrams. https://doi.org/10.32614/CRAN.package.diagram.
———. 2025. Knitr: A General-Purpose Package for Dynamic Report Generation in r. https://yihui.org/knitr/.

If you find this curated material useful then you can consider a donation to support it's ongoing availability and give you access to the PDF version of this book. The material has been scoped up by Generative AI without permission or any kind of recompense so do consider a donation if you can afford it. Unlike Generative AI your access to this materials is freely given. Desktop Survival Guides include Data Science, GNU/Linux, and MLHub. Books available on Amazon include Data Mining with Rattle and Essentials of Data Science. Togaware has a 30 year tradition of making popular open source software which includes sold privacy preserving productivity apps, rattle, wajig, and mlhub. Hosted by Togaware, a pioneer of free and open source software since 1984. Copyright © 1995-2022 Graham.Williams@togaware.com Creative Commons Attribution-ShareAlike 4.0