Things learned today:

  • Emacs tutorial: M-x help-with-tutorial
  • Learning about R today to look at crude oil data over the past year. I wanted to see if there was an opportunity to invest in airlines after crude prices had started to fall.
  • File extensions aren’t necessary to run scripts (Python, R, etc.), they are a convention.
  • REPLs are useful for exploratory programming because of their quick feedback.
  • R Cheatsheet:
    • q() - Quit REPL
    • list.files() - ls
    • source(“filename”) - Run program
    • install.packages(“packagename”), update.packages()
    • Assign variables via <-
    • c() - Create a new vector (array). Vector indices start at 1.
    • Rscript - Run program without entering REPL.
    • Graphs generated in the REPL appear immediately in Quartz, and from rscript are saved as PDFs.
    • RStudio seems like the best R-specific IDE right now. Ggplot2 is a good way to create visualizations.