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)
+ }
+ }
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