Homework 02: Explore Gapminder and use R markdown
Overview
Consult the general homework guidelines.
Due sometime Tuesday 2015-09-29. Before class is better but get help in class or office hours of you need it.
The goal is to explore a new-to-you dataset. In particular, to establish workflows based on data.frame. You will make several figures with ggplot2. You will learn how to author a dynamic report in R Markdown and share it on the web.
Remember the sampler concept. Your homework should serve as your own personal cheatsheet in the future for things to do with a new dataset. Give yourself the cheatsheet you deserve!
Bring rectangular data in
Work with the gapminder data we explored in class. If you really want to, you can explore a different dataset but get permission from Jenny. Self-assess the suitability of your dataset by reading this issue.
The Gapminder data is distributed as an R package from CRAN.
Install it if you have not done so already and remember to load it.
install.packages("gapminder")
library(gapminder)Smell test the data
Explore the gapminder object:
- Is it a data.frame, a matrix, a vector, a list?
- What’s its mode, class?
- How many variables/columns?
- How many rows/observations?
- Can you get these facts about “extent” or “size” in more than one way? Can you imagine different functions being useful in different contexts?
- What flavor is each variable?
Explore individual variables
Pick at least one categorical variable and at least one quantitative variable to explore.
- Characterize what’s possible, i.e. all possible values or max vs. min … whatever’s appropriate.
- What’s typical? What’s the spread? What’s the distribution? Etc., tailored to the variable at hand.
- Feel free to use summary stats, tables, figures. We’re NOT expecting high production value (yet).
Explore various plot types
See the ggplot2 tutorial, which also uses the gapminder data for ideas. But I want to see you exploring multiple types of plot.
But I want to do more!
This is just for people who want to take things further! NOT REQUIRED!
Do more statistical summarization and visual exploration. For example, start to look at the relationships between variables.
Read What I do when I get a new data set as told through tweets from SimplyStatistics to get some ideas!
Report your process
You’re encouraged to reflect on what was hard/easy, problems you solved, helpful tutorials you read, etc.
Submit the assignment
Follow instructions on How to submit homework
Rubric
Our general rubric applies, but also …
Check minus: Hits the elements listed above in a really minimal or rote way, maybe even with a few mistakes/omissions. And/or it’s hard to figure out which file I’m even supposed to be looking at.
Check: Hits all the elements. No obvious mistakes. Pleasant to read. No heroic detective work required. Solid.
Check plus: Some “above and beyond”, creativity, etc. You learned something new from reviewing their work and you’re eager to incorporate it into your work now.