Hello,
Inline.
Em 05-12-2016 17:09, David Winsemius escreveu:
On Dec 5, 2016, at 7:29 AM, John Sorkin <jsor...@grecc.umaryland.edu> wrote:
Rui,
I appreciate your suggestion, but eliminating the deparse statement does not
solve my problem. Do you have any other suggestions? See code below.
Thank you,
John
mydf <-
data.frame(id=c(1,2,3,4,5),sex=c("M","M","M","F","F"),age=c(20,34,43,32,21))
mydf
class(mydf)
myfun <- function(frame,var){
call <- match.call()
print(call)
indx <- match(c("frame","var"),names(call),nomatch=0)
print(indx)
if(indx[1]==0) stop("Function called without sufficient arguments!")
cat("I can get the name of the dataframe as a text string!\n")
#xx <- deparse(substitute(frame))
print(xx)
cat("I can get the name of the column as a text string!\n")
#yy <- deparse(substitute(var))
print(yy)
# This does not work.
print(frame[,var])
# This does not work.
print(frame[,"var"])
# This does not work.
col <- xx[,"yy"]
# Nor does this work.
col <- xx[,yy]
print(col)
}
myfun(mydf,age)
When you use that calling syntax, the system will supply the values of whatever
the `age` variable contains. (And if there is no `age`-named object, you get an
error at the time of the call to `myfun`.
Actually, no, which was very surprising to me but John's code worked
(not the function, the call). And with the change I've proposed, it
worked flawlessly. No errors. Why I don't know.
Rui Barradas
You need either to call it as:
myfun( mydf , "age")
# Or:
age <- "age"
myfun( mydf, age)
Unless your value of the `age`-named variable was "age" in the calling
environment (and you did not give us that value in either of your postings), you would
fail.
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