Lab 03 - Graphics
CPP 526: Foundations of Data Science I
This lab introduces core plotting functions in order to create customized graphics in R.
You can create a new RMarkdown file, or download the LAB-03 RMD template:
Functions
You will use the following functions:
Data
The data comes from the Lahman baseball data package. The Teams dataset contains season statistics for each baseball team from the late 1800s onward. The graph reports average strike-outs per game, which is calculated as ave.so below:
You will need only the average strike-outs per game, and the year variables:
| Min. | 1st Qu. | Median | Mean | 3rd Qu. | Max. | NA’s |
|---|---|---|---|---|---|---|
| 0 | 3.476 | 4.951 | 4.811 | 6.089 | 9.525 | 120 |
Note that you don’t have to understand baseball to make the graphic.
Lab Instructions
Your task is to replicate as closely as possible the graphic published by the NYT.
1. Plot average strike-outs by year.
Use 1900 as the starting year for the graph and 2025 as the end point using the xlim=c() argument in the plot.window() function.
ave.so.min <- min( ave.so, na.rm=T )
ave.so.max <- max( ave.so, na.rm=T )
plot.new()
plot.window( xlim=c( 1920, 1980 ), ylim=c( ave.so.min, ave.so.max ) )
points( year, ave.so )
2. Use the gray() function to select a shade of gray and add transparency to the points.
ave.so.min <- min( ave.so, na.rm=T )
ave.so.max <- max( ave.so, na.rm=T )
plot.new()
plot.window( xlim=c( 1920, 1980 ), ylim=c( ave.so.min, ave.so.max ) )
points( year, ave.so, col=gray( level=0.2, alpha=0.1 ), pch=17, cex=3 )
3. Add a year axis under your graph using the axis() function (try side=1).
plot.new()
plot.window( xlim=c( 1920, 1980 ), ylim=c( ave.so.min, ave.so.max ) )
points( year, ave.so, col=gray( level=0.2, alpha=0.1 ), pch=17, cex=3 )
axis( side=1 )
4. Create grid lines for your y-axis using the abline() function. The argument h=c() allows you to specify the location of your horizontal lines.
plot.new()
plot.window( xlim=c( 1920, 1980 ), ylim=c( ave.so.min, ave.so.max ) )
points( year, ave.so, col=gray( level=0.2, alpha=0.1 ), pch=17, cex=3 )
abline( h=c(3,4,5,6,7,8), lty=2, col="gray" )
5. Using the title() function to add the main title “Strikeouts On the Rise” at the top.
plot.new()
plot.window( xlim=c( 1920, 1980 ), ylim=c( ave.so.min, ave.so.max ) )
points( year, ave.so, col=gray( level=0.2, alpha=0.1 ), pch=17, cex=3 )
axis( side=1 )
title( main="some title" )
6. The league average for each year is calculated for you below. Use the points() function to highlight the league trend line and the argument type=“b” to connect each year.
# create the league average vector
league.ave <- tapply( X=ave.so, INDEX=as.factor(year), FUN="mean", na.rm=T )
league.year <- as.numeric( names( league.ave ) )
plot.new()
plot.window( xlim=c( 1920, 1980 ), ylim=c( ave.so.min, ave.so.max ) )
points( year, ave.so, col=gray( level=0.2, alpha=0.1 ), pch=17, cex=3 )
points( league.year, league.ave, type="b", pch=8, col="red" )
7. Use the text() and segments() functions to reproduce at least two of the narrative texts from the graphic (“US enters World War I”, etc.). Note that a line break within text is created by including “\n” in your string.
For example:
Your final plot should be as similar as possible to the NYT graphic!
Hints
If you need help looking up arguments remember these two helpful functions:
Submission Instructions
Login to Canvas at http://canvas.asu.edu and navigate to the assignments tab in the course repository. Upload your HTML file and RMD file to the appropriate lab submission link.
Remember to:
- name your files according to the convention: Lab-##-LastName.Rmd
- show your solution, include your code.
- do not print excessive output (like a full data set).
- follow appropriate style guidelines (spaces between arguments, etc.).