If you need to create a plot where you have a several groups of data that you want to distribute along the ‘y’ axis, but bin into one of several categories in x then you can do the following:
1) create a .csv file with your data in columns (you can use headers)
2) import the .csv file into R with: TEST <- read.table(“yourfile.csv”, sep=’,’, header=TRUE)
3) do the dotplot: dotplot(values ~ ind, data=stack(TEST), jitter.x=TRUE)
The important point here is the use of the “stack” function. This converts vectors into factors; it also lets you create the type of dotplot where the data is plotted along ‘y’ while having the same ‘x’ value.