The R Book Data Input精选.pdfVIP

3 Data Input You can get numbers into R through the keyboard, from the Clipboard or from an external file. For a single variable of up to 10 numbers or so, it is probably quickest to type the numbers at the command line, using the concatenate function c like this: y - c (6,7,3,4,8,5,6,2) For intermediate sized variables, you might want to enter data from the keyboard using the scan function. For larger data sets, and certainly for sets with several variables, you should make a dataframe externally (e.g. in a spreadsheet) and read it into R using read.table (p. 139). 3.1 Data input from the keyboard The scan function is useful if you want to type (or paste) a few numbers into a vector called x from the keyboard: x -scan() 1: At the 1: prompt type your first number, then press the Enter key. When the 2: prompt appears, type in your second number and press Enter, and so on. When you have put in all the numbers you need (suppose there are eight of them) then simply press the Enter key at the 9: prompt. 1: 6 2: 7 3: 3 4: 4 5: 8 6: 5 7: 6 8: 2 9: Read 8 items The R Book, Second Edition. Michael J. Crawley. © 2013 John Wiley Sons, Ltd. Published 2013 by John Wiley Sons, Ltd. 138 THE R BOOK You can also use scan to paste in columns of numbers from the Clipboard. In the spreadsheet, highlight the column of numbers you want, then type Ctrl + C (the accelerator keys for Copy). Now go back into R. At the 1: prompt just type Ctrl + V (the accelerator keys for Paste) and the numbers will be scanned into the named variable (x in this example). You can then paste in another set of numbers, or press Return to complete data entry. If you try to re