CODEWITHSUNDEEP
r
AdamO
AdamO

Reputation: 4930

How to "return the environment" from `with`

I am using R to scrub data. I have a dataset with 1,000s of columns all of which have some modification. I find the $ operator makes my code unreadable. I like to do data steps with the with command, so that all the elements of the data frame are locally scoped (forgive my near complete ignorance of computer science here). However, after all is done, I would like to return all the variables I wrote in the with step and possibly overwrite whichever ones I pulled in earlier. I notice the ls() command only looks at vars defined inside the with step, but how can I concatenate them into a dataframe?

As an example of desired output:

set.seed(123)
myDat <- data.frame('x'=rnorm(3))
y <- with(myDat, {
  xgt0 <- x > 0
  x2 <- x^2
  foo()
})

print(y)
          x1  xgt0         x2
1 -0.5604756 FALSE 0.31413295
2 -0.2301775 FALSE 0.05298168
3  1.5587083  TRUE 2.42957161

Upvotes: 1

Views: 42

Answers (2)

Onyambu
Onyambu

Reputation: 79208

 transform(myDat,xgt0=x > 0,x2= x^2)
           x  xgt0         x2
1 -0.5604756 FALSE 0.31413295
2 -0.2301775 FALSE 0.05298168
3  1.5587083  TRUE 2.42957161

Upvotes: 1

G. Grothendieck
G. Grothendieck

Reputation: 269556

Use within like this:

set.seed(123)
myDat <- data.frame('x'=rnorm(3))

within(myDat, {
  xgt0 <- x > 0
  x2 <- x^2
})

giving:

           x         x2  xgt0
1 -0.5604756 0.31413295 FALSE
2 -0.2301775 0.05298168 FALSE
3  1.5587083 2.42957161  TRUE

Upvotes: 6

Related Questions