[R] (Newbie) scope of with()

[Antonio Prioglio]

Hi list,
As I understand statements within with() are local to what is enclosed 
within its expression.

As some excellent examples given to me previously have illustrated it is 
nevertheless possible to assign the evaluation of an expression to an 
external variable like x <- with(data, if(..))

During a "normalisation" phase of data read from a database I have a long 
list of statements of the type
participant$longfieldname[is.na(participant$longfieldname)]<-expr(...)
or similar that makes cumbersome reading. (participant is a table of 
demographic data)

If there a neat way to do something of the sort
"participant<-with(participant,{...})"

it would make nicer reading.

Apparently attach(), detach() would not do as
fieldname<-expr(fieldname)
creates a new variable and not a change to the value of the field!

Saluti,
Antonio Prioglio

-- 
We are what we repeatedly do. Excellence, then, is not an act, but a habit.
							Aristoteles


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