starting a packrat project from outside the project directory

[Murat Tasan]

Hi all ---

I want to be able to launch a packrat project (non-interactively, via Rscript), but from any arbitrary directory on my system.

For example, imagine this scenario:

/home/me/A/B/my_packrat_project

, and there exists this file:

/home/me/A/B/my_packrat_project/main.R

I'd like to be able to run main.R (via Rscript) from any current PWD, e.g. if my PWD is /home/me, then:

Rscript A/B/my_packrat_project/main.R

To force reading of the packrat project's .Rprofile, I can do this:

R_PROFILE_USER=A/B/my_packrat_project/.Rprofile && Rscript A/B/my_packrat_project/main.R

But(!), packrat's source() command in the .Rprofile is only locally-aware... it expects one to source that file from within the packrat package:

source("packrat/init.R")

I don't want to switch working directories during the script's execution, so I thought about:

(1) copying the PWD to be passed as a command-line argument to main.R,

(2) switch to the project directory, start R,

(3) then at the start of main.R, use setwd() to jump back to PWD for execution.

It's a super-kludgey workaround, though, so I thought I'd ask to see if/how others have dealt with this previously.

Thoughts?

Cheers,

-Murat

[Kevin Ushey]

Hi Murat,

We intentionally wanted to keep the .Rprofile as clean as possible, to avoid clutter / 'scaring' users -- we hide as much logic as possible within `packrat/init.R` -- and ensuring a sub-process is called within the project directory seems like not that 'bad' of a workaround.

That said, we are open to proposals to make the startup more flexible -- perhaps, the `init.R` script could respect some command line arguments.

Thoughts?

Kevin

[Holger Hoefling]

For what is the init exactly all needed. For the analysis work - simply pointing to the right library directory using .libPaths() should be sufficient, right? And when people actually want to install from github or snapshot - one can just load packrat specifically for that. Or would I be breaking something with this approach?

Best

Holger