Hi, If I have the following data.frame
>y time val 1 08:00:05.834 1 2 08:03:13.345 2 3 08:10:12.443 3 > and the following function which converts the time string to the number of milliseconds since midnight > str_to_millis function( s ) { a <- as.numeric( unlist( strsplit(s,":",fixed="TRUE") ) ) m <- a[1]*3600000 + a[2]*60000 + a[3]*1000 } Then to get the time into millis since midnight I am doing this > transform( y, time=str_to_millis( as.character(time) ) ) time val 1 28805834 1 2 28805834 2 3 28805834 3 but this is obviously wrong, as I get all the time values as the first element converted rather than each element converted. Any ideas please? Many thanks, David ______________________________________________ R-help@r-project.org mailing list 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.