Your syntax on the 'if' is wrong; you need 'if (..expression..)' -- you are
missing the parentheses.  Also read up on functions; any changes are local
-- you cannot change values outside the environment.  You should just
return values.  You also probably need to pass in the dataframe you want to
make changes to.

Probably what you want is:

new_week <- function(df, x, y){
   # x & y are character strings with the names of the columns to
check/change
   df[[x]][is.na(df[[x]])] <- df[[y]][is.na(df[[x]])]
   df  # return value
}

# then call with assignment of the result
df <- new_week(df, 'wk5', 'wk4')




Jim Holtman
Data Munger Guru

What is the problem that you are trying to solve?
Tell me what you want to do, not how you want to do it.

On Sun, Feb 28, 2016 at 6:08 PM, KMNanus <kmna...@gmail.com> wrote:

> I’m a newbie and trying to execute this simple function in order to change
> wk 5 NA’s to wk 4 values for the dataset (ken) below.  Can someone pls tell
> me what I’m doing wrong?  The error msg is “"rror: unexpected input in
> "new_week <- function(x,y) { “
> Even the “E” is missing in the word “Error."
>
> new_week <- function(x,y) {
> if x[is.na(x)] {
> x = y
> }
> }
>
> patient wk1     wk2     wk3     wk4     wk5
> A       1       2       4       6       8
> B       2       3       NA      3       17
> C       3       4       5       11      NA
> D       4       NA      6       12      11
> E       5       6       7       NA      21
> F       6       7       8       3       NA
> G       7       8       9       7       NA
>
>
>
> Ken
> kmna...@gmail.com
> 914-450-0816 (tel)
> 347-730-4813 (fax)
>
>
>
> ______________________________________________
> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.

        [[alternative HTML version deleted]]

______________________________________________
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.

Reply via email to