[R] error when copy and transform within a data frame

[Jeff Newmiller]

See ?ifelse.

Your num_value function needs to be rewritten in vector form using ifelse.

"Al R" <anevare1 at yahoo.com> wrote:

>
># trying to do a copy and a transform within a data frame, but getting the
>"arguments imply differing number of rows" error, and I'm not sure why
>
>a=c(1,2,3)
>b=c(2,3,4)
>c=c("Yes","No","Yes")
>d=c("No","Yes","No")
>
>df=data.frame(a,b,c,d)
>
># the following works fine!
>df = transform(df, new=sapply(df[,c(1,2)], FUN = function(x) { x^2 } ))
>
># but the following doesn't work:
>
>num_value = function(x) {
>	if (x == "Yes") { return(1) }
>	else  if (x == "No") { return(0) }
> 	else return(NA)
>}
>
>df = transform(df, new=sapply(df[,c(3,4)], FUN = num_value ))
>
># generates this error..  
>Error in data.frame(list(a = c(1, 2, 3), b = c(2, 3, 4), c = c(2L, 1L,  : 
>  arguments imply differing number of rows: 3, 2
>
># thanks for the help!
>
>-- 
>View this message in context: http://r.789695.n4.nabble.com/error-when-copy-and-transform-within-a-data-frame-tp2293686p2293686.html
>Sent from the R help mailing list archive at Nabble.com.
>
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