→ Introduction to R
pdf notes on R: A Programming Environment for Data Analysis and Graphics. The official CRAN intro by Venables et al..
→ Advanced R
Companion website by H. Wickham.
→ Writing R packages
Useful information on the topic by H. Wickham. And more on the topic:
→ Writing R extensions
→ Making simple packages
→ Making packages under Windows
→ esoteric R
Doing things well in R, compiled by J. Ryan.
→ Using C code in R
Short pdf guide to the .C interface by R. Peng & J. de Leeuw.
→ R cheat sheets
on various topics, by RStudio.
→ R CRAN packages
overview by name for thousands of R packages on the CRAN repository.
→ R bioconductor packages
overview by name for thousands of R packages listed by bioconductor.
→ Software licences
→ Shiny tutorial #1
on how to use R outputs interactively in a web browser, by RStudio.
→ Shiny tutorial #2
by P. Hiemstra.
makes package development easier.
→ Interactive isotope pattern calculation
based on the R enviPat package.
→ Interactive homologue series detection
based on the R nontarget package.
for MS file conversion and centroidization.
lists plenty of open-source software tools for mass spectrometric analysis.