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Suppose I have a character string of a subsetted object name. For example: 

foo$var1[foo$var2 < 10 & foo$var3 %in% c(0:100)]  #is currently represented as...
"foo$var1[foo$var2 < 10 & foo$var3 %in% c(0:100)]"

I want to call the subsetted object using the character string of the object's name.

I tried using get():

get("foo$var1[foo$var2 < 10 & foo$var3 %in% c(0:100)]")

but I get the error:

Error in "foo$var1[foo$var2 < 10 & foo$var3 %in% c(0:100)]":
object  "foo$var1[foo$var2 < 10 & foo$var3 %in% c(0:100)]" not found

I'm assuming there is a way to do this using subsetted objects (vs. just an object name, which I know works).

Thanks in advance!

theforestecologist
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    How did you get yourself in this situation? Putting R code into strings isn't something one might consider a good strategy in R. The `get()` functions returns variables of a given name, it does not evaluate code (and operations like `[` and `&` and `<` are functions in R). You might be able to parse and eval, `eval(parse(text=x))`, but that's not something I would recommend necessarily. – MrFlick Jul 27 '15 at 19:22

1 Answers1

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As mentioned in comments by @MrFlick, you can do this:

eval(parse(text="foo$var1[foo$var2 < 10 & foo$var3 %in% c(0:100)]"))

parse turns the string into an expression and eval evaluates that expression.

Though, this is commonly considered a bad practice in R see here

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Boxuan
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