如何检查当前会话 R 中加载的文件 .rdata 的名称

Question

I have a folder with many *.rdata files, by clicking on them I directly open a workspace. Because I open many of them at the same time I would like to know the name of .rdata file associated with each R console/workspace. Is there a way to display the .rdata filename in the windows top bar, or at least check it with a command?

Answer 1

I don't think there's an automatic or easy way to find out. But you can try to find the likely culprits assuming that (a) each .Rdata file contains something unique variable(s) names, and (b) loading each file (temporarily) won't be time-prohibitive.

A quick setup:

iris2 <- iris
mtcars2 <- mtcars
save(mtcars2, file="~/Downloads/mtcars.Rdata")
save(iris2, file="~/Downloads/iris.Rdata")

I clicked on mtcars.Rdata , and up came RStudio.

ls()
# [1] "mtcars2"         

Now the "hack":

list_of_vars <- sapply(list.files(pattern = "*.Rdata"),
  function(f) {
    e <- new.env(parent = emptyenv())
    load(f, envir = e)
    ls(envir = e)
  }, simplify = FALSE)
list_of_vars
# $iris.Rdata
# [1] "iris2"
# $mtcars.Rdata
# [1] "mtcars2"

Filter(function(x) all(exists(x)), list_of_vars)
# $mtcars.Rdata
# [1] "mtcars2"

This suggests that the file I double-clicked on is mtcars.Rdata . (This is by far neither robust nor fool-proof. If you have variable name commonality, you may be out of luck.)

Update :

Since your .Rdata files have similar or identical variable names (if not contents), then you can adapt the above technique to check if that objects themselves are identical, not just the presence of the variable names.

New setup:

mtcars2 <- mtcars
save(mtcars2, file="mtcars1.Rdata")
mtcars2$mpg[1] <- 21.1
save(mtcars2, file="mtcars2.Rdata")

Check contents:

VERBOSE <- TRUE
vars_equal <- sapply(list.files(pattern = "*.Rdata"),
                     function(f) {
                       if (VERBOSE) message(f)
                       e <- new.env(parent = emptyenv())
                       load(f, envir = e)
                       all(sapply(names(e), function(varname) exists(varname, envir = .GlobalEnv) && identical(e[[varname]], get(varname, envir = .GlobalEnv))))
                     })
vars_equal
# mtcars1.Rdata mtcars2.Rdata 
#         FALSE          TRUE 

If your objects are large then this will result in a momentary spike in memory usage. As soon as R garbage collects, all of the temporary environments (and therefore the objects within each .Rdata file) created inside the outer sapply should be cleared. (This could easily be cleaned up, not just for memory management but also just cleaner more robust execution. I'm not claiming coding-excellence in this :-)

Answer 2

Good question! I'm asking this myself too! Unfortunatelly, I don't know of a better solution than to parse it from the command-line arguments with which the R process was started:

commandArgs()
# [1] "C:\\Program Files\\R\\R-4.0.4\\bin\\x64\\RGui.exe"                                    
# [2] "--workspace=D:\\tomas\\ces\\gen_dat-full_test-model3,N=2000,seed=123,tr=0.6xAll.Rdata"

pat <- "^--workspace="
sub(pat, "", grep(pat, commandArgs(), value = TRUE))
# [1] "D:\\tomas\\ces\\gen_dat-full_test-model3,N=2000,seed=123,tr=0.6xAll.Rdata"

Definitely not an ideal solution (I came here to look for a better one), but since noone has posted better solution yet, I'm posting this.