R、RStudio：以编程方式在 R 的 32 位和 64 位版本之间切换

Question

Is there a function that, within RStudio, restarts the R console in 64-bit mode or 32-bit mode without re-opening RStudio (or at least automatically re-opening it if that can't be avoided)?

I commonly run in 32-bit when using RODBC so that I can retrieve data from an Access database, but would like to otherwise leverage the capabilities of 64-bit mode for all other tasks while still in RStudio.

Answer 1

You could save the part of your code that you wish to execute using the 32-bit executable into a new script. For example, I have a script called myscript.r which will just print which version of the R executable (64 or 32-bit) which was used to run it:

cat(as.character(version[2]))

Of course you could replace this with the part of your code dealing with RODBC .

Now the main way to programmatically run a script with a custom executable is to invoke a command to the OS terminal or shell . This command should contain:

• Which executable to invoke, in our case R 32-bit (the Rscript.exe file contained in the i386 folder of your R_HOME directory)
• Arguments accepted by this executable, such as the path to the R script we want to run using this executable.

The path of myscript is "c:/gp/trash/myscript.r" , and my 32-bit R executable is

paste0(Sys.getenv("R_HOME"), "/bin/i386/Rscript.exe)
C:/PROGRA~1/R/R-40~1.4/bin/i386/Rscript.exe

I can run this script using:

myscript <- "c:/gp/trash/myscript.r"
output <- system(paste0(Sys.getenv("R_HOME"), "/bin/x64/Rscript.exe ", myscript), wait = FALSE, invisible = FALSE, intern = T)
output
[1] "x86_64"

output_32 <- system(paste0(Sys.getenv("R_HOME"), "/bin/i386/Rscript.exe ", myscript), wait = FALSE, invisible = FALSE, intern = T)
output_32
[1] "i386"

So as you can see we're executing this script from two different executables. In practice I'd suggest to save the results of your ODBC queries to a file, which you can read in your main x64 R session.

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Just a little vocabulary if you don't know some of these terms:

The terms terminal or shell are often used interchangeably. In RStudio, if you click on the terminal tab next to console , you'll be able to enter commands that will be processed by a shell .

• Shell commands are instructions that instruct the system to do some action.
• A shell is a user interface for accessing the services of an operating system.
• A terminal is a wrapper program that runs a shell and allows us to enter commands.

sources: terminal, console and cli , shell commands , scripting with r , this stackoverflow answer