Empirical Legal Studies (Fall 2025)

1-summarizing and subsetting.R

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#	CODE SNIPPETS FROM IN-CLASS EXERCISES
#	Empirical Legal Studies (Fall 2025)
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## reading in datasets

# when reading in CSV files you need to assign to an object
# filename is the full path on your computer 
x <- read.csv("filename.csv")

# reading in a dataset from the Internet -- include full URL
x <- read.csv("http://www.dougspencer.org/data/penguins.csv")

# when loading an RData file the object will be howeer it was saved
load("filename.RData")

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## saving datasets

# must specifcy which object you are saving (here "x")
write.csv(x, file = "filename.csv")
save(x, file = "filename.RData")


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## summarizing data: Election Law Professors

# read in dataset
x <- read.csv("~/Downloads/election_profs.csv")

# see the dimensions of the data (rows x columns)
dim(x)

# preview the first 6 rows of the data
head(x)

# evaluate casebook usage (equivalent to Excel Pivot Table)
table(x$Casebook)

# evaluate casebook usage by years taught
table(x$Casebook, x$Years)


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# subsetting data
x <- x[2, 5]  # this will just show you the 2d row and the 5th column
x <- x[2, ]   # this will show the entire second row (blank column argument means all columns)
x <- x[ , 5]  # this will show you all rows of column 5

x[x$Years == 11, -2]  # this will show all rows where year = 2011 and all columns except columns 2

# saving to new object
new.object <- x[x$Year == 11, ]  # this will create new object of the subset for year = 11 and all columns (because columns is blank)