Fine-tuning your terminal
Maybe you only use your terminal emulator for R.
You type R followed by Enter after you open your terminal.
It could be easier still!
Right click and choose Preferences on Xfce terminal or Profiles -> Profile preferences on gnome terminal. Under the General tab of Xfce terminal or the Command tab of gnome terminal, check Run a custom command instead of my shell. In the field for the custom command, type /usr/bin/R.
That's it! R now starts up automatically when you open a terminal.
Of course, when you close R you also close the terminal.
Don't do this if you want your shell!
I run /usr/bin/byobu as a custom command in Xfce terminal.
I keep gnome terminal as a generic bash terminal.