User manual

Chapter 3: Interacting with statistical programs 24
2. Otherwise, if the variable ess-directory stores the name of a directory (ending in a
slash), this value is used. The default for this variable is nil.
3. Otherwise, the working directory of the current buffer is used.
If ess-ask-for-ess-directory has a non-nil value (as it does by default) then the
value determined by the above rules provides the default when prompting for the starting
directory. Incidentally, ess-directory is an ideal variable to set in ess-pre-run-hook.
If you like to keep a record of your S sessions, set the variable ess-ask-about-transfile
to t, and you will be asked for a filename for the transcript before the ESS process starts.
[User Option]ess-ask-about-transfile
If non-nil, as for a file name in which to save the session transcript.
Enter the name of a file in which to save the transcript at the prompt. If the file doesn’t
exist it will be created (and you should give it a file name ending in ‘.St’); if the file already
exists the transcript will be appended to the file. (Note: if you don’t set this variable but
you still want to save the transcript, you can still do it later — see Section 4.2.4 [Saving
transcripts], page 27.)
Once these questions are answered (if they are asked at all) the S process itself is started
by calling the program name specified in the variable inferior-ess-program. If you need
to pass any arguments to this program, they may be specified in the variable inferior-
S_program_name -args (e.g. if inferior-ess-program is "S+" then the variable to set is
inferior-S+-args. It is not normally necessary to pass arguments to the S program; in
particular do not pass the ‘-e’ option to Splus, since ESS provides its own command history
mechanism.
By default, the new process will be displayed in the same window in the current frame. If
you wish your S process to appear in a separate variable, customize the variable inferior-
ess-own-frame. Alternatively, change inferior-ess-same-window if you wish the process
to appear within another window of the current frame.