[R] in which column is an entry?

[Christian Schulz]

Yes, many thanks i have really to  avoid think in loops  :-)
christian


Am Samstag, 31. Januar 2004 16:57 schrieb Chuck Cleland:
> Christian Schulz wrote:
> > df  is a data.frame with 43 colums and 29877 rows with lot of NA.
> > I want the column number for all respondendts in one column
> > where is the first entry >=0 as columnnumber.
> >
> > my first step:
> >  time <- function(df)
> > +     {        for (i in 1:length(df [,1])) {
> > +     which(df[i,1]:df[i,43] >= 0)
> > +     }
> > +            }
> >
> >>t1 <-  time(YS)
> >
> > Error in df[i, 1]:df[i, 43] : NA/NaN argument
>
>    I am not sure, but I think you might want something like this:
>
> t1 <- apply(df, 1, function(x){
>              ifelse(all(is.na(x)) | all(na.omit(x) < 0),
>              NA, which(x >= 0))})
>
> hope this helps,
>
> Chuck Cleland