
So, how is the package turning it's name into those commands?
Does the installation automatically list the src directory and iteratively
run a loop over each file and call 'R CMD SHLIB objectOfIterator' ?
The reason this is so important is because itšs easy to get things to work
via a terminal command 'R CMD SHLIB someSourceFile.cppš, so I want to be
able to take things that work that way and put them inside a package. It
seems peculiar to me that R needs to access functions through a C wrapper
too. Išm not sure why it canšt access C++ functions directly. What R is
doing is over my head because it is calling functions that were not compiled
into it. I mean, if I want to call a C or C++ function from C++ code, I have
to convince my compiler that I have a header and all definitions behind the
declarations in my source files to compile my own programs. I donšt know how
R works when the program is compiled way in advance and is then somehow
calling on declarations made later in another place. I think objective C/C++
allows for this type of thing where you can write code to call something
that is declared but not yet defined. However, Išm not sure what R is doing?
Is R doing the same thing a compiler would do and creating itšs own binary
instructions for the launch of a function, or is it creating a new
executable and launching that as itšs own application and then somehow
communicating with it?
Sean 


On 4/21/11 7:52 AM, "Dirk Eddelbuettel" <edd@debian.org> wrote:

> 
> On 21 April 2011 at 07:16, Duncan Murdoch wrote:
> | On 11-04-20 11:33 AM, Sean Robert McGuffee wrote:
> | > Hi, apparently I sent my question about using R and C++ to the wrong list,
> | > ironically seeing as that list was called Rcpp. Anyway, I was directed to
> | > post my question here. To summarize my current question, I have found two
> | > commands that I want to be able to put into a package. The commands are 'R
> | > CMD SHLIB X.cc X_main.cc' and
> | > 'dyn.load(paste("X",.Platform$dynlib.ext,sep="")),' which I would like to
> | > run when my package is installed and maybe have the second command run
> again
> | > when my package is to be used. I've been trying to figure out the
> | > documentation and learn through examples, but I'm just not getting it and
> | > have been trying for weeks.
> | > Does anyone on this site have any suggestions for me?
> | 
> | Assuming those lines work on their own, just do the following:
> | 
> | 1.  Put those *.cc files into the src directory of your package.  (You
> | may need to create it.)
> | 
> | 2.  Put useDynLib(foo) into the NAMESPACE file of your foo package.
> | 
> | 3.  Call those functions using .C("X", args, PACKAGE="foo").
> | 
> | That's it.
> 
> We told Sean this twice or three times already over in this thread
> 
>   http://thread.gmane.org/gmane.comp.lang.r.rcpp/1808
> 
> but the message does not seem to sink in.  He keeps asking where to put 'R
> CMD SHLIB' and doesn't seem to hear when we say there is none in a package...
> 
> Dirk 
>  
> | Duncan Murdoch
> | 
> | > Thanks, Sean
> | >
> | > |On 20 April 2011 at 10:20, Sean Robert McGuffee wrote:
> | > |
> | > |
> | > | Hi, thanks!
> | > |
> | > |>On 4/20/11 10:03 AM, "Steve Lianoglou"<mailinglist.honeypot@gmail.com>
> | > wrote:
> | > |>  Hi,
> | > |>
> | > |>  On Wed, Apr 20, 2011 at 9:49 AM, Sean Robert McGuffee
> | > |>  <sean.mcguffee@gmail.com>  wrote:
> | > |>>  Hi, I have a quick couple of questions about some of the
> documentation
> | > on
> | > |>>  the web page:
> | > |>>
> | > 
> http://cran.r-project.org/doc/manuals/R-exts.html#Linking-GUIs-and-other-fro
> | > n
> | > |>>  t_002dends-to-R
> | > |>>  under the heading:
> | > |>>  5.6 Interfacing C++ code
> | > |>>
> | > |>>  Question 1:
> | > |>>  If Išm at a terminal, I can type the instructions they suggest:
> | > |>>  R CMD SHLIB X.cc X_main.cc
> | > |>>  If I wanted a package to do this, how would I tell the package to do
> | > that
> | > |>>  same thing?
> | > |>
> | > |>  Just to make sure we're all on the same page, you want an R package to
> | > |>  compile some source code into a shared library/dll from inside R?
> | > |>
> | > |>  Not sure if there's a "baked in" way for that to happen, but maybe you
> | > |>  can invoke `R CMD WHATEVER` from inside R using the `system` function:
> | > |>
> | > |>  R>  ?system
> | > |>
> | > |
> | > | ok, so where in the package would I put the system call in the package
> to
> | > | have it run when installing the package?
> | >
> | >> You don't. As I said, 'R CMD INSTALL' et all do that.
> | >> Download an existing package with source, install it.  Study its sources,
> | >> study the 'Writing R Extensions' manual.  Ask on r-devel.
> | >> Basic R questions are off-topic here.
> | >
> | > |>>  Would I use the same command and just include it in a file somewhere
> in
> | > the
> | > |>>  package?
> | > |>>  If so, which file?
> | > |>
> | > |>  Hmm ... I'm curious what you're trying to do, exactly?
> | > |
> | > | I'm trying to figure out how take commands such as " R CMD SHLIB X.cc
> | > | X_main.cc" followed by "dyn.load(paste("X", .Platform$dynlib.ext, sep =
> | > | ""))," which are commands I can get to work for myself as a human
> | > | interactively, and put the commands into a package to be automatically
> run
> | > | when installing the package. I mean, it's great if I can compile a c++
> | > file
> | > | and then use it inside R, but I'm only doing that so I can let other
> | > people
> | > | do that via a package. As much as I read this documentation, I keep
> | > missing
> | >
> | >> Again, I like working from an existing, working package. As I said, there
> are
> | >> almost 1000 to pick from.
> | >> Please direct follow-ups that have no bearing on Rcpp to r-devel.
> | >> Dirk
> | >
> | > I've tried to figure this out for weeks by looking at other packages and
> | > reading the confusing and nonintegrated documentation, but it hasn't
> taught
> | > me how to put the two commands into a package so that they are run when
> the
> | > package is installed. I'm simply trying to find out where in my package I
> | > should put the commands 'R CMD SHLIB X.cc X_main.cc' and
> | > 'dyn.load(paste("X",.Platform$dynlib.ext,sep="")),'
> | > in order to have them run when my package is installed.
> | >
> | >
> | > | the connections between the different sections. This is a section I am
> | > | loving because it works very well. Thus, I want to figure out how to
> take
> | > | the baby steps I'm doing and combine them into a package. Specifically,
> I
> | > | want to take these two commands and insert them into a package so that
> | > these
> | > | commands will compile my code and make a dynamic ".so" file where R can
> | > | access its functions when others install my package.
> | > |
> | > |>
> | > |>>  Question 2:
> | > |>>  dyn.load(paste("X", .Platform$dynlib.ext, sep = ""))
> | > |>>
> | > |>>  Where does .Platform$dynlib.ext come from?
> | > |>>  What does it mean?
> | > |>>  What do itšs components .Platform and $dynlib and .ext mean?
> | > |>
> | > |>  .Platform is lust a normal list -- it is defined internally (I guess).
> | > |>  You can access "named" elements of a list with `$`.
> | > |>
> | > |>  .Platform$dynlyb (or .Platform[['dynlib']]) tells you the extension
> | > |>  your particular system uses for shared libraries:
> | > |>
> | > |>  R>  .Platform
> | > |>  $OS.type
> | > |>  [1] "unix"
> | > |>
> | > |>  $file.sep
> | > |>  [1] "/"
> | > |>
> | > |>  $dynlib.ext
> | > |>  [1] ".so"
> | > |>
> | > |>  $GUI
> | > |>  [1] "X11"
> | > |>
> | > |>  $endian
> | > |>  [1] "little"
> | > |>
> | > |>  $pkgType
> | > |>  [1] "mac.binary.leopard"
> | > |>
> | > |>  $path.sep
> | > |>  [1] ":"
> | > |>
> | > |>  $r_arch
> | > |>  [1] "x86_64"
> | > |>
> | > |>  See ?.Platform for more help.
> | > |
> | > | Ah, thanks, that clarifies exactly what .Platform$dynlib.ext is, it's
> | > ".so"
> | > | on my system.
> | > |
> | > | This, the dyn.load(paste("X", .Platform$dynlib.ext, sep = "")) is
> | > equivalent
> | > | to the command dyn.load("X.so) which now makes sense in that context!
> | > |
> | > |
> | > | _______________________________________________
> | > | Rcpp-devel mailing list
> | > | Rcpp-devel@lists.r-forge.r-project.org
> | > | https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel
> | >
> | 
> | ______________________________________________
> | R-devel@r-project.org mailing list
> | https://stat.ethz.ch/mailman/listinfo/r-devel


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