Specifying Windows only compatibility in the R package DESCRIPTION file - r

I am including a binary executable with a package that I am creating. I have specified its path in the /inst/ package subfolder using a file named BinaryFiles located in the root of the package installation.
Is it necessary to note elsewhere that it will only run under Windows (both 32 and 64 bit architectures) e.g. in the DESCRIPTION file? (In addition to the documentation where this will be stated repeatedly!)
e.g. as:
SystemRequirements: Windows
or something to that effect?

There is a optional entry in DESCRIPTION specifying the operating system that is meant for this. So please see Section 1.1.1 of 'Writing R Extensions' for full details -- but in short, you want to use
OS_type=windows
here.

Related

R check for a package: optimize the way DLLs are built and checked

I want to optimize my process for building a package. I have in pckgname/src some fortran code (f90):
pckgname/src/FortranFile1.f90
pckgname/src/FortranFile2.f90
I am under RStudio. When I build the package, it creates the src-i386 and src-x64 folders, inside which executable files in .o are produced
pckgname/src-i386/FortranFile1.o
pckgname/src-i386/FortranFile2.o
pckgname/src-x64/FortranFile1.o
pckgname/src-x64/FortranFile2.o
then dll files are produced into each of these folders from the .o files:
pckgname/src-i386/dllname.dll
pckgname/src-x64/dllname.dll
thereafter if I want to check the code successfully, I need to manually copy paste the dll into these two folders (in the previous version of the question i wrote code instead of dll which might have led to misunderstandings)
pckgname/inst/libs/x64/dllname.dll
pckgname/libs/X64/dllname.dll
My question is: is it normal that I have to do this or is there a shorter way without having to copy paste by hand dllname.dll
into these two folders? It could be indeed a source of error.
NB: If i don't copy the dlls into the said folders I get the following error messages (translated from the French):
Error in inDL(x, as.logical(local), as.logical(now), ...) :
impossible to load shared object 'C:/Users/username/Documents/pckgname/inst/libs/x64/dllname.dll':
LoadLibrary failure: The specified module can't be found
Error in inDL(x, as.logical(local), as.logical(now), ...) :
impossible to load shared object 'C:/Users/username/Documents/pckgname/libs/x64/dllname.dll':
LoadLibrary failure: The specified module can't be found.
[...]
`cleanup` is deprecated
The short answer
Is it normal that I have to do this?
No. If path/to/package is the directory you are developing your package in, and you have everything set up for your package to call your Fortran subroutines correctly (see "The long answer"), you can run
R CMD build path/to/package
at the command prompt, and a tarball will be constructed for you with everything in the right place (note you will need Rtools for this). Then you should be able to run
R CMD check packagename_versionnumber.tar.gz
from the command prompt to check your package, without any problems (stemming from the .dll files being in the wrong place -- you may have other problems, in which case I would suggest asking a new question with the ERROR, WARNING, or NOTE listed in the question).
If you prefer to work just from R, you can even
devtools::check("path/to/package")
without having to run devtools::build() or R CMD build ("devtools::check()... [b]undles the package before checking it" -- Hadley's chapter on checking; see also Karl Broman's chapter on checking).
The long answer
I think your question has to do with three issues potentially:
The difference between directory structure of packages before and after they're installed. (You may want to read the "What is a package?" section of Hadley's Package structure chapter -- luckily R CMD build at the command prompt or devtools::build() in R will take care of that for you)
Using INSTALL vs. BUILD (from the comments to the original version of this answer)
The proper way to set up a package to call Fortran subroutines.
You may need quite a bit of advice on the process of developing R packages itself. Some good guides include (in increasing order of detail):
Karl Broman's R package primer
Hadley Wickham's R packages
The Writing R Extensions manual
In particular, there are some details about having compiled code in an R package that you may want to be aware of. You may want to first read Hadley's chapter on compiled code (Broman doesn't have one), but then you honestly need to read most of the Writing R Extensions manual, in particular sections 1.1, 1.2, 1.5.4, and 1.6, and all of chapters 5 and 6.
In the mean time, I've setup a GitHub repository here that demonstrates a toy example R package FortranExample that shows how to correctly setup a package with Fortran code. The steps I took were:
Create the basic package structure using devtools::create("FortranExample").
Eliminate the "Depends" line in the DESCRIPTION, as it set a dependence on R >= 3.5.1, which will throw a warning in check (I have now also revised the "License" field to eliminate a warning about not specifying a proper license).
Make a src/ directory and add toy Fortran code there (it just doubles a double value).
Use tools::package_native_routine_registration_skeleton("FortranExample") to generate the symbol registration code that I placed in src/init.c (See Writing R Extensions, section 5.4).
Create a nice R wrapper for using .Fortran() to call the Fortran code (placed in R/example_function.R).
In that same file use the #' #useDynLib FortranExample Roxygen tag to add useDynLib(FortranExample) to the NAMESPACE file; if you don't use Roxygen, you can put it there manually (See Writing R Extensions 1.5.4 and 5.2).
Now we have a package that's properly set up to deal with the Fortran code. I have tested on a Windows machine (running Windows 8.1 and R 3.5.1) both the paths of running
R CMD build FortranExample
R CMD check FortranExample_0.0.0.9000.tar.gz
from the command prompt, and of running
devtools::check("FortranExample")
from R. There were no errors, and the only warning was the "License" issue mentioned above.
After cleaning up the after-effects of running devtools::check("FortranExample") (for some reason the cleanup option is now deprecated; see below for an R function to handle this for you inspired by devtools::clean_dll()), I used
devtools::install("FortranExample")
to successfully install the package and tested its function, getting:
FortranExample::example_function(2.0)
# [1] 4
The cleanup function I mentioned is
clean_source_dirs <- function(path) {
paths <- file.path(path, paste0("src", c("", "-i386", "-x64")))
file_pattern <- "\\.o|so|dll|a|sl|dyl"
unlink(list.files(path = paths, pattern = file_pattern, full.names = TRUE))
}
No, it is not normal and there is a solution to this problem. Make use of Makevars.win. The reason for your problem is that .dlls are looking for dependencies in places defined by environment variable PATH and relative paths defined during the linking. Linking is being done when running the command R CMD INSTALL as it is stated in Mingw preferences plus some custom parameters defined in the file Makevars.win (Windows platform dependent). As soon as the resulting library is copied, the binding to the places where dependent .dlls were situated may become broken, so if you put dlls in a place where typically dependent libraries reside, such as, for instance, $(R_HOME)/bin/$(ARCH)/,
cp -f <your library relative path>.dll $(R_HOME)/bin/$(ARCH)/<your library>.dll
during the check R will be looking for your dependencies specifically there too, so you will not miss the dependencies. Very crude solution, but it worked in my case.

R 3.1.2 library file

I need to link to R library and have seen some pointers on the Web - all referencing Rdll.lib file.
However, in my installation directory \R\R-3.1.2\bin\x64 contains only DLL file - R.dll.
Does the default installation of R ships a library and if yes, where to find it?
As a note, this all relates to attempts to create an R wrapper for C++ library with SWIG
You need to manually build the Rdll.lib. Instruction can be found in R folder in the doc/README.packages (at least for my 3.1.3 R installation):
First build the import library Rdll.lib by (from the sources)
make R.exp
lib /def:R.exp /out:Rdll.lib
or, depending on your version of VC++:
link /lib /def:R.exp /machine:x86 /out:Rdll.lib

What type of object is an R package?

Probably a pretty basic question but a friend and I tried to run str(packge_name) and R threw us an error. Now that I'm looking at it, I'm wondering if an R package is like a .zip file in that it is a collection of objects, say pictures and songs, but not a picture or song itself.
If I tried to open a zip of pictures with an image viewer, it wouldn't know what to do until I unzipped it - just like I can't call str(forecast) but I can call str(ts) once I've loaded the forecast package into my library...
Can anyone set me straight?
R packages are generally distributed as compressed bundles of files. They can either be in "binary" form which are preprocessed at a repository to compile any C or Fortran source and create the proper headers, or they can be in source form where the various required files are available to be used in the installation process, but this requires that the users have the necessary compilers and tools installed at locations where the R build process using OS system resources can get at them.
If you read the documentation for a package at CRAN you see they are distributed in set of compressed formats that vary depending on the OS-targets:
Package source: Rcpp_0.11.3.tar.gz # the Linus/UNIX targets
Windows binaries: r-devel: Rcpp_0.11.3.zip, r-release: Rcpp_0.11.3.zip, r-oldrel: Rcpp_0.11.3.zip
OS X Snow Leopard binaries: r-release: Rcpp_0.11.3.tgz, r-oldrel: Rcpp_0.11.3.tgz
OS X Mavericks binaries: r-release: Rcpp_0.11.3.tgz
Old sources: Rcpp archive # not really a file but a web link
Once installed an R package will have a specified directory structure. The DESCRIPTION file is a text file with specific entries for components that determine whether the local installation meets the dependencies of the package. There are NAMESPACE, LICENSE, and INDEX files. There are directories named '/help', '/html', '/Meta', '/R', and possibly '/libs', '/demo', '/data', '/unitTests', and others.
This is the tree at the top of the ../library/Rcpp package directory:
$ ls
CITATION NAMESPACE THANKS examples libs
DESCRIPTION NEWS.Rd announce help prompt
INDEX R discovery html skeleton
Meta README doc include unitTests
So in the "life-cycle" of a package, there will be initially a series of required and optional files, which then get processed by the BUILD and CHECK mechanisms into an installed package, which than then get compressed for distribution, and later unpacked into a specified directory tree on the users machine. See these help pages:
?.libPaths # also describes .Library()
?package.skeleton
?install.packages
?INSTALL
And of course read Writing R Extensions, a document that ships with every installation of R.
Your question is:
What type of object is an R package?
Somehow, I’m still missing an answer to this exact question. So here goes:
As far as R is concerned, an R package is not an object. That is, it’s not an object in R’s type system. R is being a bit difficult, because it allows you to write
library(pkg_name)
Without requiring you to define pkg_name anywhere prior. In contrast, other objects which you are using in R have to be defined somewhere – either by you, or by some package that’s loaded either explicitly or implicitly.
This is unfortunate, and confuses people. Therefore, when you see library(pkg_name), think
library('pkg_name')
That is, imagine the package name in quotes. This does in fact work just as expected. The fact that the code also works without quotes is a peculiarity of the library function, known as non-standard evaluation. In this case, it’s mostly an unfortunate design decision (but there are reasons).
So, to repeat the answer: a package isn’t a type of R object1. For R, it’s simply a name which refers to a known location in the file system, similar to what you’ve assumed. BondedDust’s answer goes into detail to explain that structure, so I shan’t repeat it here.
1 For super technical details, see Joshua’s and Richard’s comments below.
From R's own documentation:
Packages provide a mechanism for loading optional code, data and
documentation as needed.…A package is a directory of files which
extend R, a source package (the master files of a package), or a
tarball containing the files of a source package, or an installed
package, the result of running R CMD INSTALL on a source package. On
some platforms (notably OS X and Windows) there are also binary
packages, a zip file or tarball containing the files of an installed
package which can be unpacked rather than installing from sources. A
package is not a library.
So yes, a package is not the functions within it; it is a mechanism to have R be able to use the functions or data which comprise the package. Thus, it needs to be loaded first.
I am reading Hadley's book Advanced-R (Chapter 6.3 - functions, p.79) and this quote will cover you I think:
Every operation is a function call
“To understand computations in R, two slogans are helpful:
Everything that exists is an object.
Everything that happens is a function call."
— John Chambers
According to that using library(name_of_library) is a function call that will load the package. Every little bit that has been loaded i.e. functions or data sets are objects which you can use by calling other functions. In that sense a package is not an object in any of R's environments until it is loaded. Then you can say that it is a collection of the objects it contains and which are loaded.

R install package question

I'm trying to install infochimp library on my R.
(*from drewconway-infochimps-13d899c.zip - infochimp folder contains folders man, R and files DESCRIPTION, LICENSE, NAMESPACE)
I have installed:
-Developers toolkit
-RJSONIO
-RCURL
-twitteR
However, when I copy the library directly to the relevant directory (same technique as I used for RJSONIO) it doesn't show up in the install package menu.
On Windows platform
Thanks.
Assuming you were using dashes rather than backslashes to designate directory location and that the actual file name is "13d899c.zip" and the full path to that file is "\from drewconway\infochimps\" then in an open session of R try this:
install.packages(pkgs="\\from drewconway\\infochimps\\13d899c.zip" )
(Paths in R under Windows need to have either doubled backslashes or single forward slashes. Packages in zip format should be in binary format which is the default type. You should learn to be more careful about how you communicate the path construction and if the "\from drewconway\" guess is wrong, then correct it.)

change to newer Tcl/Tk version in R

I have multiple versions of tcl and tk installed in my tcl.framework and tk.framework 8.4, 8.5 and 8.6.
On top of this, I am using R and it is always complaining with the following error
"In fun(...) : Can't find a usable tk.tcl in the following directories:"
The multiple "directories" in which it looks are incorrect and it is not even the correct version it is looking for. What I would like to do is to tell R the correct "version" I want it to use and the "correct path" it should look for the tcl/tk files.
I was tempted to add a new directory to the R-Tcl/Tk search path with "addTclPath("/custom/TclTk/path")" but how do I tell it I want it to search to a different path and use "the new" version of tcl/tk from that moment.
I am using MACOSX 10.6.
This is described in the R Installation and Administration Manual:
http://cran.r-project.org/doc/manuals/R-admin.html#Tcl_002fTk
The relevant section in R version 2.13.0 Patched (2011-04-19 r55523) begins with this.
A.2.1 Tcl/Tk
The tcltk package needs Tcl/Tk >= 8.4 installed: the sources are available at http://www.tcl.tk/. To specify the locations of the Tcl/Tk files you may need the configuration options . . .
Sounds like you're using an incomplete installation of Tk. Because Tk doesn't (by default) work as just a library, but a library with supporting script files, it needs to be installed correctly for it to function. Once you're using an installed version, that message should go away. (OTOH, OSX does include a proper build of Tk as a framework IIRC; a bit old, but correct. On my OSX machine, this configuration option would work: --with-tk-config=/Library/Frameworks/Tk.framework/tkConfig.sh)

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