usmap: US Map
In jian13579/HutchinHill: A Cloropleth Map of Williams Students

Takes in two years worth of datasets and returns a map of the US States that maps the difference of the two datasets

1	usmap(currentyear, oldyear, title = "", save = FALSE, interactive = FALSE)

`currentyear`	The vector of a dataset for the most current year
`oldyear`	The vector of a dataset for the year you want to compare to
`title`	The title of the plot and the name which the plot is saved to
`save`	TRUE to save, FALSE to not
`interactive`	TRUE to choose the interactive mode in viewer, FALSE to view in just the default plot

a s4 object that has the difference of the datasets mapped to it

1 2	##Creating the map of the US with data from 2001 and 2002 usmap2000.2002 <- usmap(yearsdata$X2001, yearsdata$X2000, title = "Change in Students 2000-2001")