Hi Don,
Thanks for your message.
> First fact:
?> R understands relative paths (as do the other languages you mentioned)
(you have misunderstood R if you think it doesn't)?
I never said R doesn't understand relative paths (which software
doesn't...). I simply said it is not straightforward to use relative paths
in R as the function 'MyOwnPath()' returning the path of the R file
where this function is written and run doesn't exist; therefore workarounds
more or less "clean" are necessary. Precisely changing (automatically,
not manually of course) the current working directory to the location where a
given R file (.R) is located is not straightforward.
> Second fact:?
?> R interprets relative paths as being relative to its current working
directory
Yep.
> Third fact:
?> To find out R's current working directory type: getwd() at the R
prompt
Yep.
> The easiest way to set the working directory, in my opinion, is by starting
R from a linux or Mac command shell (bash, tcsh, etc) environment. You start R
by typing "R" at the shell prompt and R's working directory is
inherited from the current working directory of the shell.
Yes, I found a similar but more user-friendly (in my opinion) way via .Rproj
(with RStudio) and .RData (with R GUI).
> No additional packages are necessary in order to manage R's working
directory simply and effectively.
Exactly!
Best regards,
Olivier
________________________________
De : MacQueen, Don <macqueen1 at llnl.gov>
Envoy? : lundi 8 octobre 2018 16:04
? : Olivier GIVAUDAN; r-help at r-project.org
Objet : Re: [R] Genuine relative paths with R
A few facts (and some opinions):
First fact:
R understands relative paths (as do the other languages you mentioned) (you
have misunderstood R if you think it doesn't)
Second fact:
R interprets relative paths as being relative to its current working directory
Third fact:
To find out R's current working directory type: getwd() at the R prompt
Fourth fact:
There are various ways to set R's working directory, depending on how you
are running R. Once R is running, you can if necessary use setwd() at the R
prompt, and this is platform-independent (but it should rarely be necessary).
The easiest way to set the working directory, in my opinion, is by starting R
from a linux or Mac command shell (bash, tcsh, etc) environment. You start R by
typing "R" at the shell prompt and R's working directory is
inherited from the current working directory of the shell.
If you are using a GUI (i.e., you started R by double-clicking on some icon),
look for menu commands to set the working directory. Check the documentation for
the GUI to find out other ways to set the working directory for that GUI.
No additional packages are necessary in order to manage R's working
directory simply and effectively.
Yes, you can move all the scripts related to some project as a whole to some
other location and have them run seamlessly using relative paths. Hopefully it
is clear by now that all that is needed is to set R's working directory to
the project's main directory.
-Don
--
Don MacQueen
Lawrence Livermore National Laboratory
7000 East Ave., L-627
Livermore, CA 94550
925-423-1062
Lab cell 925-724-7509
?On 10/6/18, 4:48 AM, "R-help on behalf of Olivier GIVAUDAN"
<r-help-bounces at r-project.org on behalf of olivier_givaudan at
hotmail.com> wrote:
Dear R users,
I would like to work with genuine relative paths in R for obvious reasons:
if I move all my scripts related to some project as a whole to another location
of my computer or someone else's computer, if want my scripts to continue to
run seamlessly.
What I mean by "genuine" is that it should not be necessary to
hardcode one single absolute path (making the code obviously not
"portable" - to another place - anymore).
For the time being, I found the following related posts, unfortunately never
conclusive or even somewhat off-topic:
https://stackoverflow.com/questions/1815606/rscript-determine-path-of-the-executing-script
https://stackoverflow.com/questions/47044068/get-the-path-of-current-script/47045368
http://r.789695.n4.nabble.com/Script-auto-detecting-its-own-path-td2719676.html
So I found 2 workarounds, more or less satisfactory:
1. Either create a variable "ScriptPath" in the first lines of
each of my R scripts and run a batch (or shell, etc.) to replace every single
occurrence of "ScriptPath <-" by "ScriptPath <- [Absolute
path of the R script]" in all the R scripts located in the folder (and
possibly subfolders) of the batch file.
2. Or create an R project file with RStudio and use the package
"here" to get the absolute path of the R project file and put all the
R scripts related to this project in the R project directory, as often
recommended.
But I am really wondering why R doesn't have (please tell me if I'm
wrong) this basic feature as many other languages have it (batch, shell, C,
LaTeX, SAS with macro-variables, etc.)?
Do you know whether the language will have this kind of function in a near
future? What are the obstacles / what is the reasoning for not having it
already?
Do you know other workarounds?
Best regards,
Olivier
[[alternative HTML version deleted]]
______________________________________________
R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
[[alternative HTML version deleted]]