Looping through files in R

Question

I am using R to calculate the mean values of a column in a file like so:

R
file1 = read.table(\"x01\")
mean(file1$V4)

However I have no experie

Answer 1

My solution is also similar to @jmsinger but you can specify the path to your files in the code itself and then calculate the mean like this :

filename <- system("ls /dir/",intern=TRUE)

for(i in 1:length(filename)){

file <- read.table(filename[i],header=TRUE) ## if you have headers in your files ##
mean <- mean(file$V4)

write.table(mean,file=paste("/dir",paste("mean",filename[i],sep="."),sep="/")) 
##if you wish to write the means of all the files in seperate files rather than one.
}

hope this helps