Statistics and Data Analysis for Microarrays Using R and Bioconductor, 2nd Edition

Introduction to R 149

Note that, if the entire path of the file is not specified, R will try to find it

in the current directory which initially is something like “c:\R” (in Windows,

the current directory can be changed from the File menu of the R window).

From the command line, the directory can be changed with setwd:

> old=getwd()

> setwd("c:/Users/Sorin")

> getwd()

[1] "c:/Users/Sorin"

> setwd(old)

As another observation, the read.table function has a header=T/F op-

tion that tells the function whether the file contains a header or not. If the

argument header=TRUE, the co ntent of the first line will be used as variable

names (column names). However, the function is smart enough to auto-detect

whether the file has a header. In particular, if the first row