Common questions on HW1

1. R Studio freezes.

2. Break long code into multiple lines.

What’s the result of following R code?

x <- 1 + 2
  + 3 + 4
x

How about?

x <- 1 + 2 + 
  3 + 4
x

1. Pass string arguments to R from command line.

2. Wifi UCLA-Web blocks port 8787 used by R Studio server.

About debugging

• Remember: it’s always always you, never the computer.

• Be systematic. Build on incremental changes.

• Be sure it’s fixed, running without an error is not fixed!

• Be tenacious, you’ll find it … eventually.

Tips on HWs

• Start early!

• Ask for help. You are most likely to get good help if you provide a minimal reproducible example.

  https://stackoverflow.com/help/mcve

  https://stackoverflow.com/questions/5963269/how-to-make-a-great-r-reproducible-example

Questions from last lecture

• Control width of output in Knit.

Today

• Data visualization with ggplot2.

• Data transformation with dplyr.