[R] Problem in installing and starting Rattle

[Tony Plate]

On Mon, Mar 7, 2011 at 6:57 AM, nerice <neil.rice at plymouth.ac.uk> wrote:
> CHECK FOR CONFLICTS IN YOUR PATH !!!
>
> I had a related problem when trying to use library "RGtk2" for the first
> time.  My problem was that when loading the library R was looking for the
> file "zlib1.dll" but couldn't find the procedure to launch RGtk2. I was
> getting an "Entry Point not found" error from Rgui.exe.
>
> The reason was because I had another package in my PATH environment variable
> (C:\program files\Intel\WiFi\bin) which had a CONFLICTING version of the
> "zlib1.dll" - and it was looking in this file and not the "zlib1.dll" which
> came with GTK+.
>
> Removed this conflict from the PATH and all was ok.
>
>

I also had a related problem trying to use libary RGtk2 under Windows XP.

I kept getting the message "unable to load shared object
C:\R\site-library\RGtk2\libs\i386\RGtk2.dll"

Uninstalling and reinstalling various versions of GTK2, both through R
and outside R, many times, did not help.

With the help of Neil Rice's comment, I found that there was another
version of zlib1.dll in a directory on my PATH.  Removing that
directory from the path (inside R) fixed the problem and RGtk2 runs
fine now.

Here's an R expression to look for other copies on zlib1.dll on the path:

> with(list(x=file.path(strsplit(Sys.getenv("PATH"), ";")$PATH, "zlib1.dll")), x[file.exists(x)])
[1] "C:\\R\\GTK2-Runtime\\bin/zlib1.dll"
>

There are many ways to modify the PATH.  To set PATH inside R:

> Sys.setenv(PATH=paste(grep("UNWANTED\\\\PATH", strsplit(Sys.getenv("PATH"), ";")[[1]], value=T, invert=T), collapse=";"))

(substitute some pattern that matches the unwanted directory for
"UNWANTED\\\\PATH", remembering to use four backslashes to match one).

-- Tony Plate