03. Functions

[briatte]

• 3.0 Functions, e.g.
  • Math
  • Data
  • Models – introduce formula notation
  • quickly mention plots, HTTP calls, whatever
• 3.1 Control flow
  • The Human Narrative: # comments
  • The Computer Narrative: %>% pipe operator
  • Conditions: if/else, else_if, mutate_if, when
  • Sanity Checks: stopifnot – quickly mention unit tests for packages
• 3.2 Iteration (with mentions of parallelization)
  • Loops: for, while – mention parallelization with foreach
  • Vectorization: sapply, lapply, mapply, map_* – parallelization with mcapply
  • Need for Speed? mention benchmarking
  • Reproducible Code:
    • Reproducibility = 10% code, 90% human documentation
    • Writing pseudo-makefiles for a data analysis folder
    • Makefiles + cron (with demo scraper)
• Practice
• Currently: Computing the Herfindhal-Hirschman Index
• Add: Examples of calls using Stan, Julia, Python, shell?
• Add: Game of Life example to show iteration and matrix computations (Petr Keil)