cm009 2014-10-01 Wednesday overview

• HW04 will be due before class Monday 2014-10-06 Wednesday 2014-10-08. Will be to write a function, documenting process from interactive pilot to formal tests. Apply function to Gapminder using plyr. Watch Twitter. Now posted here.
• Writing your own functions! The exciting conclusion
  • Write your own R functions, part 1 done Monday
  • Write your own R functions, part 2 done Monday
  • Write your own R functions, part 3 TODAY
  • Function-writing Practicum TODAY
• Data aggregation
  • Big picture slides linked and embedded below
  • Guided challenge: write function to regress life expectancy on year and return the estimated intercept and slope
  • Use plyr::ddplyr() to apply this function to each country in Gapminder
• What’s left for 545? these topics are on the horizon
  • More data aggregation
  • Tidy data
  • File I/O
  • Be the boss of your factors
  • Back to figs: effective graphs, be the boss of colors