From hin-tak.leung at cimr.cam.ac.uk  Mon Apr 16 13:15:27 2007
From: hin-tak.leung at cimr.cam.ac.uk (Hin-Tak Leung)
Date: Mon, 16 Apr 2007 12:15:27 +0100
Subject: [Rd] how to control which version of a package
	library()	installs?
In-Reply-To: <Pine.LNX.4.64.0704132252050.17244@auk.stats>
References: <461FED8C.2040603@acm.org>	<Pine.LNX.4.64.0704132204150.18247@gannet.stats.ox.ac.uk>	<461FFA29.8040401@acm.org>
	<Pine.LNX.4.64.0704132252050.17244@auk.stats>
Message-ID: <46235ACF.9060408@cimr.cam.ac.uk>

Prof Brian Ripley wrote:
<snipped>
> 
> We should try to explain this, but there is another level of complexity.
> If a package has compiled code, unloading the namespace is unlikely to 
> unload the DLL (it would need to be done explicitly in .onUnload).
> And even then, as I understand it there are OSes on which you cannot 
> really unload DLLs, and certainly cannot load another DLL of the same name 
> into the process: you get the previously loaded one.
<snipped>

On this, I am quite sure I have managed to crash wine on linux by
dyn.load() an updated version of a DLL of the same name with win32 R in
wine. It is obviously a useful thing to be able to change the source,
re-compile it, and load a new version into R, so that's why I did it,
I think. (and it does work with native R on linux). Genuine windows
may or may not crash, but I don't usually sit in front of windows
for development...

HTL



[Rd] how to control which version of a package library() installs?
Hin-Tak Leung