R Error in x$ed : $ operator is invalid for atomic vectors

Here is my code:

x<-c(1,2) x names(x)<- c("bob","ed") x$ed 

Why do I get the following error?

Error in x$ed : $ operator is invalid for atomic vectors

7 Answers

From the help file about $ (See ?"$") you can read:

$ is only valid for recursive objects, and is only discussed in the section below on recursive objects.

Now, let's check whether x is recursive

> is.recursive(x) [1] FALSE 

A recursive object has a list-like structure. A vector is not recursive, it is an atomic object instead, let's check

> is.atomic(x) [1] TRUE 

Therefore you get an error when applying $ to a vector (non-recursive object), use [ instead:

> x["ed"] ed 2 

You can also use getElement

> getElement(x, "ed") [1] 2 

The reason you are getting this error is that you have a vector.

If you want to use the $ operator, you simply need to convert it to a data.frame. But since you only have one row in this particular case, you would also need to transpose it; otherwise bob and ed will become your row names instead of your column names which is what I think you want.

x <- c(1, 2) x names(x) <- c("bob", "ed") x <- as.data.frame(t(x)) x$ed [1] 2 

Because $ does not work on atomic vectors. Use [ or [[ instead. From the help file for $:

The default methods work somewhat differently for atomic vectors, matrices/arrays and for recursive (list-like, see is.recursive) objects. $ is only valid for recursive objects, and is only discussed in the section below on recursive objects.

x[["ed"]] will work.

Here x is a vector. You need to convert it into a dataframe for using $ operator.

 x <- as.data.frame(x) 

will work for you.

x<-c(1,2) names(x)<- c("bob","ed") x <- as.data.frame(x) 

will give you output of x as:
bob 1
ed 2
And, will give you output of x$ed as:
NULL
If you want bob and ed as column names then you need to transpose the dataframe like x <- as.data.frame(t(x)) So your code becomes

x<-c(1,2) x names(x)<- c("bob","ed") x$ed x <- as.data.frame(t(x)) 

Now the output of x$ed is:
[1] 2

This solution worked for me data<- transform(data, ColonName =as.integer(ColonName))

You get this error, despite everything being in line, because of a conflict caused by one of the packages that are currently loaded in your R environment.

So, to solve this issue, detach all the packages that are not needed from the R environment. For example, when I had the same issue, I did the following:

detach(package:neuralnet) 

bottom line: detach all the libraries no longer needed for execution... and the problem will be solved.

Atomic collections are accessible by $

Recursive collections are not. Rather the [[ ]] is used

 Browse[1]> is.atomic(list()) [1] FALSE Browse[1]> is.atomic(data.frame()) [1] FALSE Browse[1]> is.atomic(class(list(foo="bar"))) [1] TRUE Browse[1]> is.atomic(c(" lang ")) [1] TRUE 

R can be funny sometimes

 a = list(1,2,3) b = data.frame(a) d = rbind("?",c(b)) e = exp(1) f = list(d) print(data.frame(c(list(f,e)))) X1 X2 X3 X2.71828182845905 1 ? ? ? 2.718282 2 1 2 3 2.718282