Thus far, we've only been entering data directly into the interactive R console. For any data set of non-trivial size this is, obviously, an intractable solution. Fortunately for us, R has a robust suite of functions for reading data directly from external files.
Go ahead, and create a file on your hard disk called
favorites.txt that looks like this:
flavor,number pistachio,6 mint chocolate chip,7 vanilla,5 chocolate,10 strawberry,2 neopolitan,4
This data represents the number of students in a class that prefer a particular flavor of soy ice cream. We can read the file into a variable called
favs as follows:
> favs <- read.table("favorites.txt", sep=",", header=TRUE)
If you get an error that there is no such file or directory, ...