R has many functions that allow you to import data from other applications. The following table lists some of the useful text import functions, what they do, and examples of how to use them.
| Function | What It Does | Example |
|---|---|---|
| read.table() | Reads any tabular data where the columns are separated (for example by commas or tabs). You can specify the separator (for example, commas or tabs), as well as other arguments to precisely describe your data. | read.table(file="myfile", sep="t", header=TRUE) |
| read.csv() | A simplified version of read.table() with all the arguments preset to read CSV files, like Microsoft Excel spreadsheets. | read.csv(file="myfile") |
| read.csv2() | A version of read.csv() configured for data with a comma as the decimal point and a semicolon as the field separator. | read.csv2(file="myfile", header=TRUE) |
| read.delim() | Useful for reading delimited files, with tabs as the default separator. | read.delim(file="myfile", header=TRUE) |
| scan() | Allows you finer control over the read process when your data isn’t tabular. | scan("myfile", skip = 1, nmax=100) |
| readLines() | Reads text from a text file one line at a time. | readLines("myfile") |
| read.fwf | Read a file with dates in fixed-width format. In other words, each column in the data has a fixed number of characters. | read.fwf("myfile", widths=c(1,2,3) |
In addition to these options to read text data, the package foreign allows you to read data from other popular statistical formats, such as SPSS. To use these functions, you first have to load the built-in foreign package, with the following command:
> library("foreign")
The following table lists the functions to import data from SPSS, Stata, and SAS.
| Function | What It Does | Example |
|---|---|---|
| read.spss | Reads SPSS data file | read.spss("myfile") |
| read.dta | Reads Stata binary file | read.dta("myfile") |
| read.xport | Reads SAS export file | read.export("myfile") |