I'm writing a package that helps to quantify images using R. I would like to store example images that people can use to test the package but I'm not sure how to store them. Can anyone help?
In general you can put anything you want into the inst/ directory of a package. Let's say you make a directory inst/images in your source package, with files foo1.png, foo2.jpg, and foo3.tif. When the package is installed, you can find them via system.file(), e.g. list the available files via
list.files(system.file("images",package="your_pkg"))
or access them via e.g.
get_image <- function(fn) {
system.file("images",fn,package="your_pkg")
}
png::readPNG(get_image("foo1.png"))
The only possible pitfall I can think of is that CRAN is not enthusiastic about packages with very large footprints, which could be a problem if (1) you have a lot of large images and (2) you want to submit to CRAN.
Related
I made a package in R called "my_package_name". When I run ?my_package_name or ??_my_package_name, no results are found. I want a help file to be loaded in the same way that ?ggplot2 loads a package help file.
I can run ?my_function_name to obtain the help files for my functions. However, this does not work with my package name, even though the description file is complete. I found that help(package = my_package_name) loads a page that contains the description file and help pages, but I would like load a page with ?my_package_name.
I would say that the easiest way is probably to run the following from the usethis package. It will create the file needed to have your package documentation
usethis::use_package_doc()
I suggest reading the documentation of the function to understand what's going on under the hood.
I am currently developing an R package and want it to be as clean as possible, so I try to resolve all WARNINGs and NOTEs displayed by devtools::check().
One of these notes is related to some code I use for generating sample data to go with the package:
checking top-level files ... NOTE
Non-standard file/directory found at top level:
'generate_sample_data.R'
It's an R script currently placed in the package root directory and not meant to be distributed with the package (because it doesn't really seem useful to include)
So here's my question:
Where should I put such a file or how do I tell R to leave it be?
Is .Rbuildignore the right way to go?
Currently devtools::build() puts the R script in the final package, so I shouldn't just ignore the NOTE.
As suggested in http://r-pkgs.had.co.nz/data.html, it makes sense to use ./data-raw/ for scripts/functions that are necessary for creating/updating data but not something you need in the package itself. After adding ./data-raw/ to ./.Rbuildignore, the package generation should ignore anything within that directory. (And, as you commented, there is a helper-function devtools::use_data_raw().)
In package ISLR, there is a data set called Default.
I want to use that data set, but the ISLR package is not installed on my machine.
data(Default)
# Warning message:
# In data(Default) : data set ‘Default’ not found
library(ISLR)
# Error in library(ISLR) : there is no package called ‘ISLR’
Since I'll probably never use it again, I don't want to install the package. I thought about reading it from the web, but it's not in the linked web page from the package description.
In general, is there a way to load a data set from a package without installing the package?
You can do this from within R:
download.file("http://cran.r-project.org/src/contrib/ISLR_1.0.tar.gz",
dest="ISLR.tar.gz")
untar("ISLR.tar.gz",files="ISLR/data/Default.rda")
L <- load("ISLR/data/Default.rda")
summary(Default)
If you want to keep a copy of the data file:
file.copy("ISLR/data/Default.rda",".")
Clean up:
unlink(c("ISLR.tar.gz","ISLR"),recursive=TRUE)
I'm not sure you can get around having to download the tarball -- in principle you might be able to run untar() directly on a network connection, but I don't think the underlying machinery can actually extract a file without downloading the whole tarball to somewhere on your machine first.
You said, "Since I'll probably never use it again, I don't want to install the package." If the fact that you'll never use it again is your main concern, then perhaps this solution is not quite what you want, but it is probably the simplest solution:
Install the package with install.packages().
Extract and save the dataset that you want.
Uninstall the package with remove.packages().
So the final result is what you want in three simple steps, though the process does involve installing the package, which you hoped to avoid. But you end up without the package in your system that you don't want, so the end result is the same as what you want.
I have built an R package but I do not want my users to have to install it before using it.
Is there a way to load a package without having to install it?
For example, if I have a package mypackage.tar.gz, is there something like
library("mypackage.tar.gz")
?
I'll join in "the chorus" of suggesting you should really install the package.
That having been said, you can take a look at Hadley's devtools package, which will let you load packages into the workspace without dumping in your global workspace.
The package will have to be untar'd/unzipped and follow the standard R package structure.
In order for this to work, though, your users would have to have the devtools package installed, so ... I'm not sure that this is any type of win for you.
If you only need the code to be loaded without it being installed, take the raw R script and source it:
source(myScript.R)
If you have different functions, you can create an R script that just loads all the necessary source files. What I sometimes do when developing, is name all my functions F_some_function.R and my classes Class_some_function.R. This allows me to source a main file containing following code :
funcdir <- "C:/Some/Path"
files <- dir(funcdir)
srcfiles <- c(grep("^Class_",dir(funcdir),value=T),
grep("^F_",dir(funcdir),value=T)
)
for( i in paste(funcdir,srcfiles,sep="/")) source(i)
If you present them with the tarred file, they can untar themselves using untar() before sourcing the main file.
But honestly, please use a package. You load everything in the global environment (or in a specified environment if you use local=T), but you lose all functionality of a package. Installing a package is no hassle, and removing neither.
If it's a matter of writing rights on the C drive (which is the only possible reason not to use a package that I met in my carreer), one can easily set another library location. R 2.12 actually does this by itself on Windows. See ?.libPaths()
I'm creating an R package and I need it to include a couple of non R script files which get called by one of my functions. I need these script files to be distributed with the package, naturally. So that leaves me with two questions:
a) In which directory of the package
tree should I place these files? b) Is that location mandatory or just convention?
Do I need to change any other
settings or configurations or will
they just get copied to the
directory mentioned in #1 and then I
can figure out the path using
system.file()?
I've tried to find the answer in the Writing R Extensions document, but it didn't jump out at me. And, of course, I didn't read the whole thing. Am I being too honest here?
I think you want either exec/ at the top-level (even though that is labeled 'still experimental, or subdirectory of inst as everything in inst/ gets copied verbatim into the package.
A quick example from the packages I have expanded in source is gdata which has inst/perl, inst/xls and inst/bin. These you could then call from R itself by computing the path of the installed package using system.file().