> On Feb 25, 2017, at 8:09 AM, Ashta <sewa...@gmail.com> wrote: > > I have a data set and I want to repeat a column value based on other > column value, > > my data look like > > read.table(text = "Year month flag > 2001 1 Z > 2001 2 - > 2001 4 X > 2002 1 Z > 2002 2 - > 2003 1 - > 2003 2 Z > 2004 2 Z > 2005 3 Z > 2005 2 - > 2005 3 -", header = TRUE) > > Within year If flag = '-' then i want replace '-' by the previous > row value of flag. In this example for yea 2001 in month 2 flag is > '-' and I want replace it by the previous value of flag (i.e., 'Z') > 2001 1 Z > 2001 2 Z > 2001 4 X > > If all values of flag are '-' within year then I wan to set as N > > The complete out put result will be > > year month flag > 2001 1 Z > 2001 2 z > 2001 4 X > 2002 1 Z > 2002 2 Z > 2003 1 Z > 2003 2 Z > 2004 2 Z > 2005 3 Z > 2005 2 N > 2005 3 N > > Thank you in advance >
Your example doesn't actually match your verbal description of the algorithm because you have not specified the rule that establishes values for instances where the first value in a year is "-". The `na.locf` function in the 'zoo' package would be useful for the task describe in your verbal description when used in conjunction with the 'stats'-package's `ave` function. -- David. > ______________________________________________ > 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. David Winsemius Alameda, CA, USA ______________________________________________ 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.
