On Wed, May 16, 2012 at 3:04 PM, Simon Urbanek
<[email protected]> wrote:
> On May 16, 2012, at 1:10 PM, R. Michael Weylandt wrote:
>
>> Suppose I have the following very simple ~/.Rprofile
>>
>> .First <- function(){
>> assign("e", exp(1), .GlobalEnv)
>> lockBinding("e", .GlobalEnv)
>> }
>>
>> If I start R from the terminal, all is fine, but if I use R.app this
>> throws an error about not being able to change the assigned value of a
>> locked binding on "e". This makes me think that R.app hits .First()
>> twice -- is that the intended behavior? [You can demonstrate this with
>> cat() statements more directly, but I figured I'd show a use case]
>>
>> I don't have access to another computer right now to confirm, but the
>> difference between Terminal and R.app seems funny. If it seems to be a
>> problem with my machine, I'll hunt further.
>>
>
> It is somewhere between intention and a bug. It is caused by the necessity of
> the R.app GUI to deal with launches in a different working directory -- e.g.
> when you drag a folder on the GUI. Because the GUI has to setup R and start
> the event loop before it can accept open events it emulates the regular R
> behavior after receiving the open event by starting R with --no-restore-data
> first and then loading the workspace "by hand" and running .First(). This is
> all fine if you use your workspace to populate .First, but if you do that in
> .Renviron then .First gets called twice: first when R starts without a
> workspace and then by the GUI because it doesn't know that your .First does
> not come from the loaded workspace.
>
>
Thanks for your note, Simon. I think that I understand, but I'll dig
around in the source just to make sure. I'm likely revealing my
ignorance here, but is there any reason one or the other loads
couldn't run as R --vanilla or with the interactive() flag turned off?
[My actual .Rprofile has the whole thing wrapped in
if(interactive()){} to avoid trouble in R CMD .... scenarios] This
might be a nonsense suggestion though -- I don't really use R other
than starting a fresh workspace each time so I've never really thought
through how that would be managed.
> Obviously, an easy work-around is to check with bindingIsLocked().
Hadn't thought of this -- I'll add it to my .Rprofile
>
> That said, I have added a very, very ugly hack to work around your case in
> the GUI.
Don't uglify the code base on my account, particularly when such an
easy fix is available and I use the Terminal so much more.
Thanks again,
Michael
>
> Cheers,
> Simon
>
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