[Rd] FW: [Rcpp-devel] Question on 5.6 Interfacing C++ code

Sean Robert McGuffee sean.mcguffee at gmail.com
Thu Apr 21 17:17:19 CEST 2011 

Ah, that's simple, thanks!

On 4/21/11 10:57 AM, "Simon Urbanek" <simon.urbanek at r-project.org> wrote:

> 
> On Apr 21, 2011, at 10:52 AM, Sean Robert McGuffee wrote:
> 
>> Thanks,
>> That's great, but I don't know how to determine what foo is.
> 
> It's the name of your package.
> 
> 
>> How do I declare the name of the package?
>> 
> 
> in DESCRIPTION:
> Package: name
> 
> and the directory of your package has to have the same name - please do read
> http://r.research.att.com/man/R-exts.html#Creating-R-packages
> 
> Cheers,
> Simon
> 
> 
>> 
>> On 4/21/11 7:16 AM, "Duncan Murdoch" <murdoch.duncan at gmail.com> 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.
>>> 
>>> 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 at gmail.com>
>>>> wrote:
>>>> |>  Hi,
>>>> |>
>>>> |>  On Wed, Apr 20, 2011 at 9:49 AM, Sean Robert McGuffee
>>>> |>  <sean.mcguffee at 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-fr>>>>
o
>>>> n
>>>> |>>  t_002dends-to-R
>>>> |>>  under the heading:
>>>> |>>  5.6 Interfacing C++ code
>>>> |>>
>>>> |>>  Question 1:
>>>> |>>  If I¹m 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 it¹s 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 at lists.r-forge.r-project.org
>>>> | https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel
>>>> 
>>> 
>> 
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>

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