Please complete before the next class.
Make sure that you’ve completed all previous HW first.
Read and review your notes, my notes, and my slides over the basics of loading data into R. Answer the review questions throughout the document. Remember to practice!
- Like the previous assignment, this is a tedious assignment–you’ll need to work carefully. I suggesting spreading the exercise over several different sessions to give you time to digest the ideas. Don’t rush it. The previous assignment covered many simple ideas–this assignment covers a fewer, but more complex ideas.
- I’ve found that working in groups helps when you are stuck.
- I try to write exam questions that students who can do the review exercises will answer correctly and quickly (and that others will answer incorrectly and/or slowly).
- When you can’t get your code to work, it’s usually just a missing parenthesis or quotation mark. It’s not that you’re making a huge mistake. Huamns can sitll mkae snese wehn tehre are tpyos, but not computers! Check your code for typos carefully. Run your script one line at a time, from top to bottom, to find mistakes. As examples, most mistakes are like the following:
b <- c("Male", "Female) # missing the second " after "Female"
exp(23 # forgot to close a parentheses
log(10 base = 2) # missing comma between arguments
a <- c(1, 2, 3)
mean(A) # R is case-sensitive--there's an object "a", but no object "A"
mena(a) # misspelled function name
Mean(a) # R is case-senstive