Class 11

Analyzing data from US states

In our system we have some variables describing US states. They are:

• state.abb
• state.area
• state.center
• state.division
• state.name
• state.region
• state.x77

We want to give good descriptions of this data.

Area versus Region

Initially we can make this simple graphic

plot(state.area, col=as.numeric(state.region))

We want to add

• main title
• labels on the axis
• change numbers on the vertical axis
• include a legend explaining the symbols

Here we put a main title

plot(state.area, col=as.numeric(state.region), main="Area vs Region")

then we add labels to the axis

plot(state.area, col=as.numeric(state.region), main="Area vs Region", ylab="area [sq mi]", xlab="US state")

then we changed the units of the vector

plot(state.area/1000, col=as.numeric(state.region), main="Area vs Region", ylab="area [thousands sq mi]", xlab="US state")