First, lets create the dataset from Example 3 from scratch:
State <- c("Florida", "Hawaii", "South Carolina", "California", "North Carolina",
"Texas", "Other")
Frequency <- c(203, 51, 34, 33, 23, 16, 27)
This is sufficient to construct a basic pie chart:
pie(Frequency, labels = State, col = rainbow(7), main = "Pie Chart of Shark Attacks")
You can get a basic barchart like this,
barplot(Frequency, names.arg = State, col = rainbow(7), main = "Bar Chart of Shark Attacks")
but it is a good idea to add axis labels:
barplot(Frequency, names.arg = State, col = rainbow(7), main = "Bar Chart of Shark Attacks",
xlab = "State", ylab = "Frequency")
Often, as in the graph above, the labels don’t all fit on the x-axis. Here are some workarounds.
Make the text smaller:
barplot(Frequency, names.arg = State, col = rainbow(7), cex.names = 0.8, main = "Bar Chart of Shark Attacks",
xlab = "State", ylab = "Frequency")
Include a line break \n
in some of the longer labels:
State <- c("Florida", "Hawaii", "South \n Carolina", "California", "North \n Carolina",
"Texas", "Other")
barplot(Frequency, names.arg = State, col = rainbow(7), main = "Bar Chart of Shark Attacks",
xlab = "State", ylab = "Frequency")
Typically, a combination of these two will work.
This bar charts shows the counts of the categories on the y axis. In the book, we show percentages, which you can get like this:
Percentage <- 100 * Frequency/sum(Frequency)
barplot(Percentage, names.arg = State, col = rainbow(7), main = "Bar Chart of Shark Attacks",
xlab = "State", ylab = "Percentage (%)")