[R] Path to R script

[David Scott]

Sharpie wrote:
> 
> Johannes W. Dietrich wrote:
>> There is certainly a trivial solution for my question, but I can't 
>> find the answer in the documentation.
>>
>> I need a platform independent method to obtain the file path of the 
>> current R script.
>>
>> My working group uses R on several machines with different operating 
>> systems including Mac OS X, Windows and Linux, and for obvious 
>> reasons the file hierarchies are very different. Therefore, it would 
>> be useful to be able to address data files and external procedures 
>> relative to the path of the script.
>>
>> Thank you for any suggestion,
>>
>> J. W. D.
>> -- 
>>
> 
> The best recipie I have for dealing with this situation is:
> 
>   1. Place R scripts in a package (a very good idea anyway if you are
> distributing code to others).
> 
>   2. Place a configuration file in the package that contains info such as
> paths to data directories.
> 
>   3. Customize the configuration file after installing the package (if
> necessary).
> 
> Then your script accesses the configuration file, which is in a known fixed
> location, and uses the information inside to find other files that may be in
> unknown and changing locations.
> 
> You could also place the configuration file in a location such as:
> 
> ~/.MyPackageConf
> 
> Since:
> 
>   path.expand( '~/' )
> 
> Has a pretty predictable behavior across platforms.  This would save it from
> being overwritten every time you updated the package.
> 
> Hope this helps!
> 
> -Charlie

I also was about to suggest putting the code in a package because then 
you have system.file available, which I presume works across platforms:

 > system.file("RunTests.R",package="DistributionUtils")
[1] "/usr/local/david/R/DistributionUtils"
 > system.file("unitTests/runTests.R",package="DistributionUtils")
[1] "/usr/local/david/R/DistributionUtils/unitTests/runTests.R"


David Scott


_________________________________________________________________
David Scott	Department of Statistics
		The University of Auckland, PB 92019
		Auckland 1142,    NEW ZEALAND
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Director of Consulting, Department of Statistics