CODEWITHSUNDEEP
r
user27976
user27976

Reputation: 903

reading objects from R workspace

I loaded some objects into R workspace (of rstudio) and tried assigning to a variable (like this: x <- list("regular expression pattern forobjectName") so that the contents will be available for further analysis using merge function. R simply assigned the correct object name surrounded by quotes and merge() threw error when I passed x to it. Does anyone know which functions might be useful for reading the object which can then be assigned to a variable for further analysis?

Thanks

Upvotes: 0

Views: 372

Answers (1)

vijucat
vijucat

Reputation: 2088

The get() function retrieves an object by name. Thus, if x is 1, you can use get("x") to get 1 :

> # Typing this on the R command line...
> x <- 1
> get("x")
[1] 1

You could use get() as part of an lapply() on a list of variable names to retrieve all objects that match the pattern you are looking for. Here's example in which I merge() two data frames retrieved indirectly.

The x <- lapply(ls(pat="^df"), get) is the core statement relevant to you.

> # First we define the data frames
> df1 <- data.frame(a=1:5, b=1:5)
> df2 <- data.frame(a=3:7, b=3:7)
> ls(pat="^df")
[1] "df1" "df2"
> # This just gets their names
> x <- ls(pat="^df")
> x
[1] "df1" "df2"
> # This retrieves the actual objects
> x <- lapply(ls(pat="^df"), get)
> x
[[1]]
  a b
1 1 1
2 2 2
3 3 3
4 4 4
5 5 5

[[2]]
  a b
1 3 3
2 4 4
3 5 5
4 6 6
5 7 7

> merge(x[[1]], x[[2]])
  a b
1 3 3
2 4 4
3 5 5

Upvotes: 2

Related Questions