CODEWITHSUNDEEP
rfunction
agbarnett
agbarnett

Reputation: 180

Replacing attach() with with() in a function

I am trying to replace attach() with with() in a function. I've created a simple example below that mimics the problem. I'd like to be able to use a particularly variable from a data set, and also to be able to modify that variable (e.g., squaring or dividing by 1000 as below).

dummy.data=data.frame(CVD=1:10,pop=1:10)

# this works
working=function(data,offset){
  attach(data)
  b=offset
  print(summary(b))
  detach(data)
}
working(dummy.data,pop/1000)

# this does not work
not.working=function(data,offset){
  with(data,b=offset)
  print(summary(b))
}

not.working(dummy.data,pop/1000)

Upvotes: 0

Views: 94

Answers (1)

IRTFM
IRTFM

Reputation: 263342

This does the same operation, but the goals of this exercise remain opaque to me:

now.working=function(data,offset){
  b=offset; cat(str(b))
  with(data, print(summary(eval(b))))
}

now.working(dummy.data,expression(pop/1000) )

Upvotes: 1

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