Is it possible to execute a command automatically upon launch in R? - r

I use R from the GUI app (R.app). When I open the app, it loads some data (e.g. .Rapp.history or .RData) from the working directory. However, is it possible to execute some commands or functions automatically upon launch?
I just want to load some libraries such as ggplot2 or plyr, which I always use on my session.

You can edit your Rprofile.site and add the desired commands to the functions .Last and .First respectively.
More info about Rprofile.site: here
At startup, R will source the Rprofile.site file. It will then look for a .Rprofile file to source in the current working directory. If it doesn't find it, it will look for one in the user's home directory. There are two special functions you can place in these files. .First( ) will be run at the start of the R session and .Last( ) will be run at the end of the session.
That said, you can edit the function .First() to load the desired libraries.
.First <- function() {
library("dplyr")
library("ggplot2")
}
You can edit the same file and this command, which is used specifically for this purpose:
options(defaultPackages=c(getOption("defaultPackages"),
"dplyr","ggplot2"))

Related

How to run R projects / use their relative paths from the terminal without setwd() resp. cd

I'm kinda lost on that one:
I have set up an R project, let's call it "Test Project.Rproj". The beauty of R projects is the possibility to use relative paths (relative to the .Rproj file). My project consists of a "main.R" script, which is saved on the same level as the .Rproj file.
Additionally I have a directory called 'Output', where I want my plots and exported data to be saved. My "main.R" file looks like the following:
my_df <- data.frame(A = 1:10, B = 11:20)
my_df |>
writexl::write_xlsx(here::here("Output",
paste0("my_df_",
stringr::str_replace_all(as.character(Sys.time()), ":", ""),
".xlsx")))
My final goal is to automate the execution of the 'main.R' file using the Windows Task Scheduler. But in order to do so, I have to be able to run the script from the terminal. The problem here is the working directory. When opening an R project, all the paths are relative to .Rproj file. But in the terminal the current working directory is <C:\Users\my_name>. Of course I could manually set the working directory via cd "path\to\my\project. But I would like to avoid that.
My current call for the execution of the main.R file in the terminal is the following:
"C:\Program Files\R\R-4.1.0\bin\Rscript" -e "source('C:/Users/my_name/path/to/my/project/main.R')"
My two ideas for a solution are the following, but I am happy for other suggestions as well.
In order to replicate the usual use of a project: Is there a way to execute the .Rproj
file from the terminal? In order to create a similar environment as in RStudio, where all the relative paths are working, when executing scripts from the project afterwards?
There are two packages adressing the problem of relative paths: rprojroot and here, where the former is the basis for the latter. I am pretty sure that here does not provide the needed functionality. I tried adding here::i_am("main.R) to my main.R file, but the project root directory still is not found when executing in the terminal from a working directory outside the project.
For rprojroot to work, I think it is also necessary to have your current working directory somewhere within the project. But this package offers a lot of functionality, so I am not sure wheter I am overlooking something.
So I would be happy about any help. Maybe it is impossible and I have to change the working directory manually - then I would be glad to know that as well.
Some links I used in my research:
https://www.tidyverse.org/blog/2017/12/workflow-vs-script/
https://malco.io/2018/11/05/why-should-i-use-the-here-package-when-i-m-already-using-projects/
http://jenrichmond.rbind.io/post/how-to-use-the-here-package/
Thanks a lot!
Edit: My current implementation is an additional R script, where I manually set the working directory via setwd() and source the main.R file. However it is always suggested to avoid setwd, which is why this whole question exists.

Add script defining paths to .Rprofile

I am working on a project where I was hoping we'd be able to set file paths using the .Rprofile. I wrote a script that defines paths for specific users and since we're using renv and that puts an activate script into the profile anyways, I just added my paths.R script after that in the .Rprofile.
When I asked a colleague to open the .Rproj file to open the project, I thought it would run renv/activate.R and my paths.R script, but they're not seeing their defined paths, only mine. Am I missing something?
# contents of my .Rprofile
source("renv/activate.R")
source("paths.R")
# contents of path.R
if (Sys.info()["user"] == "francisco"){
data_dir <-
'path/to/data'
}
# etc
Any advice on workflow is welcome. Thanks!

Changing R options persistently

I want to change the prompt in R from > to R> and I know I should use the options command options(prompt="...") and it works, but then when I restart R the prompt is back to >.
Is there anyway to save the change so that it sticks?
Use .Rprofile file:
You can customize the R environment through a site initialization file or a directory initialization file. R will always source the Rprofile.site file first. On Windows, the file is in the C:\Program Files\R\R-n.n.n\etc directory. You can also place a .Rprofile file in any directory that you are going to run R from or in the user home directory.
At startup, R will source the Rprofile.site file. It will then look for a .Rprofile file to source in the current working directory. If it doesn't find it, it will look for one in the user's home directory. There are two special functions you can place in these files. .First( ) will be run at the start of the R session and .Last( ) will be run at the end of the session.
More details are here

Same R history from different workspace

I am new to R and I just figured out why my history did not contain all my previous commands. R create a .Rhistory file in each working directory.
I often change working directory and I would like to have the history of all my past sessions in the same file. Is there a simple way to do that ?
Thanks.
(I am on Mac OS 10.6 and I use Rstudio)
An easy way would be to manually save your history like this:
savehistory(file = "~/.Rhistory")
and then load it when you open an R command session:
loadhistory(file = "~/.Rhistory")
Otherwise you can edit your 'Rprofile.site' and add savehistory() and loadhistory() to the functions .Last and .First respectively.
More info about Rprofile.site: here
At startup, R will source the Rprofile.site file. It will then look for a .Rprofile file to source in the current working directory. If it doesn't find it, it will look for one in the user's home directory. There are two special functions you can place in these files. .First( ) will be run at the start of the R session and .Last( ) will be run at the end of the session.

Locate the ".Rprofile" file generating default options

In R and RStudio, I think I have messed around with the .Rprofile file a few times, and I currently am loading up an old version of it upon startup of R or RStudio, is there a way that I can quickly find the location of the file that is generating the default options?
Thanks
Like #Gsee suggested, ?Startup has all you need. Note that there isn't just the user profile file, but also a site profile file you could have messed with. And that both files can be found in multiple locations.
You could run the following to list existing files on your system among those listed on the page:
candidates <- c( Sys.getenv("R_PROFILE"),
file.path(Sys.getenv("R_HOME"), "etc", "Rprofile.site"),
Sys.getenv("R_PROFILE_USER"),
file.path(getwd(), ".Rprofile"),
file.path(Sys.getenv("HOME"), ".Rprofile"))
Filter(file.exists, candidates)
Note that it should be run on a fresh session, right after your started R, so that getwd() will return the current directory at startup. There is also the tricky possibility that your profile files do modify the current directory at startup, in which case you would have to start a "no-profile" session (run R --no-site-file --no-init-file) before running the code above.

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