If you are entering a small number of observations, entering the data directly into R might be a good approach. There are a couple of different ways to enter data into R.
Many of the examples in Parts I and II show how to create new objects directly on the R console. If you are entering a small amount of data, this might be a good approach.
As we have seen before, to create a vector, use the c function:
> salary <- c(18700000, 14626720, 14137500, 13980000, 12916666) > position <- c("QB", "QB", "DE", "QB", "QB") > team <- c("Colts", "Patriots", "Panthers", "Bengals", "Giants") > name.last <- c("Manning", "Brady", "Pepper", "Palmer", "Manning") > name.first <- c("Peyton", "Tom", "Julius", "Carson", "Eli")
It’s often convenient to put these
vectors together into a data frame. To create a data frame, use the
data.frame function to combine the vectors:
> top.5.salaries <- data.frame(name.last, name.first, team, position, salary) > top.5.salaries name.last name.first team position salary 1 Manning Peyton Colts QB 18700000 2 Brady Tom Patriots QB 14626720 3 Pepper Julius Panthers DE 14137500 4 Palmer Carson Bengals QB 13980000 5 Manning Eli Giants QB 12916666
Entering data using individual statements can be awkward for more than a handful of observations. (That’s why my example above included only five observations.) Luckily, R provides a nice GUI for editing tabular data: the data editor.
To edit an object with the data editor, use the edit function. The edit
function will open the data editor and return the edited object. For
example, to edit the top.5.salaries
data frame, you would use the following command:
> top.5.salaries <- edit(top.5.salaries)Notice that you need to assign the output of the edit function to a symbol; otherwise, the
edits will be lost. The data editor is designed to edit tabular data
objects, specifically data frames and matrices. The edit function can be used with other types of
objects, such as vectors, functions, and lists, but it will open a text
editor.
Alternatively, you can use the fix function. The fix
function calls edit on its argument
and then assigns the result to the same symbol in the calling
environment. For the example above, here is how you would use fix:
> fix(top.5.salaries)On Microsoft Windows, there is a menu item “Data Editor...” under
the Edit menu that allows you to enter the name of an object into a
dialog box and then calls fix on the
object.
The data editor on Microsoft Windows is very intuitive. To edit a value, simply click in the cell. To change the name of a column (or to change it from numeric to character), click on the column name and a window will pop up allowing you to make those changes. You may add additional rows and columns simply by entering values into empty cells (see Figure 11-1).
On Mac OS X, the edit window looks (and works) a bit differently. You may use the data editor with data frames or matrices (see Figure 11-2).
You can click on a data cell to edit the value. The buttons on the top have the following effects (from left to right): add a column, delete a column, add a row and delete a row. You can change a column’s width by clicking on the lines separating that column from its neighbor and dragging it. You cannot change variable types or names from this editor.
A data editor GUI is also available on X Windows systems. Like the Microsoft Windows version, you can edit the column names. For convenience, this editor includes Copy, Paste, and Quit buttons (see Figure 11-3).
