Question

I am plotting multiple plots:

a <- dir(pattern="stuff.*\\.txt$")
for (i in 1:length(a)) {
  b <- read.table(a[i])
  jpeg(paste("/../.../", i, ".jpg"))
  plot(b$V1,b$V2, main=?)
  dev.off()
}

I want to name all jpg & main=? with original file name. All jpgs from this code are named from 1 to N. Is their any way to do this?

Answer 1

Perhaps I’m missing something, but the variable a[i] is the original data file name. So you just need to do:

plot(b$V1, b$V2, main=a[i])

In your ‘paste’ function, the default separator is a space, so:

paste("A", "B") 

gives A B. Instead, you want: paste(A,B, sep=""). When creating the jpeg file you should remove the .txt or .csv file extension from your data. So something like:

library(tools)
fname = file_path_sans_ext(a[i])
jpeg(paste("/../.../", fname, ".jpg", sep=""))

Should work