Hi Ernie, I'll use the built in mtcars dataset for demonstrative purposes.
You have some condition, which can be used to create an index ## show data frame mtcars ## create index based on your condition i <- which(mtcars$carb == 1) ## set those rows of mtcars in your index ## to the index - 1 mtcars[i, ] <- mtcars[i - 1, ] ## show resulting data frame mtcars note that if your condition grabs the first row, this will wreck havoc. Cheers, Josh On Sat, Jul 7, 2012 at 8:20 PM, Ernie Tedeschi <ernie.tedes...@gmail.com> wrote: > I've created a data frame in R, but in order to clean up some of the data, > I need to set certain variable observations equal to the value of their > previous observation (it would be conditional, but that part's less > important right now). In Stata, I would simply set var = var[_n-1] in those > cases. What is the R equivalent? > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. -- Joshua Wiley Ph.D. Student, Health Psychology Programmer Analyst II, Statistical Consulting Group University of California, Los Angeles https://joshuawiley.com/ ______________________________________________ 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.
