Change default prompt and output line prefix in R?

Question

For the purposes of teaching and preparing written instructions about R, one of the things that's always frustrated me is that I can't simply copy commands and output from R and paste them into another R session. For example, if I do something trivial, such as

> x <- rnorm(10) > x  [1]  1.76975998  1.19722850 -0.39274507 -1.10979974  0.52320473 -0.08643833  [7]  0.94437690  0.08083207  0.62260363  1.89305469 

If I copy and paste that into a document or even here in this post, you (and my students) can not then just highlight it, copy it and paste it into an R session successfully

> > x <- rnorm(10) Error: syntax error > > x Error: syntax error >  [1]  1.76975998  1.19722850 -0.39274507 -1.10979974  0.52320473 -0.08643833 Error: syntax error >  [7]  0.94437690  0.08083207  0.62260363  1.89305469 Error: syntax error 

You might want to do this to test your installation of R, compare my output to yours, or simply to make use of a function I've offered.

So, what I'd like to be able to do is to change the default prompt from > to either an empty string or a blank space and also prefix all output lines with a hash mark #. That way, I could use R interactively to generate a session that looks like

x <- rnorm(10) x # [1]  1.76975998  1.19722850 -0.39274507 -1.10979974  0.52320473 -0.08643833 # [7]  0.94437690  0.08083207  0.62260363  1.89305469 

which could be copy/pasted into an R session successfully. It would make prepping R code for a journal article, students, lectures, etc. much easier for me (and maybe for others?)

I've poked around the documentation with no luck... any ideas? pointers?

Currently, I'm using R on a Mac either via the R.app GUI or from Terminal.

Answer 1

You might try:

options(prompt=" ", continue=" ")

Note the spaces in between the quotes.

The first option makes the prompt disappear. The second erases the "+" from appearing on long wrapping lines.