Iff dd is your data frame then: dd$prev <- ave(dd$of, dd$Id, FUN = function(x) c(NA, head(x, -1)))
On Wed, Oct 21, 2009 at 2:55 AM, clion <birt...@hotmail.com> wrote: > > Dear Rlers, > in the following dataset I would like to insert a new column that refers to > the data of the previous row. > My question is whether the probability of a female (Id) changes if she had > given birth to a pup in the previous year. So my dataframe consists of the > column Id, year (2003-2007 for each Id) and offspring (=of; 1-0): > Id year of > 1 2003 1 > 1 2004 0 > 1 2005 1 > 1 2006 1 > 1 2007 0 with 1= female (Id) gave birth to offspring (same year) > 2 2003 0 and 0 = female didn't pup > 2 2004 1 > 2 2005 1 > 2 2006 0 > 2 2007 1 > 3 2003 1 > 3 2004 1 > 3 2005 1 > 3 2006 0 > 3 2007 0 > Now I want to add the column "offspring in the previous year - yes/no(1-0)" > the output now should look like this: > > Id year of of_inPreviousYear > 1 2003 1 NA > 1 2004 0 1 > 1 2005 1 0 > 1 2006 1 1 > 1 2007 0 1 > 2 2003 0 NA > 2 2004 1 0 > 2 2005 1 1 > 2 2006 0 1 > 2 2007 1 0 > 3 2003 1 NA > 3 2004 1 1 > 3 2005 1 1 > 3 2006 0 1 > 3 2007 0 0 > > any idea how I could program that? > > thanks a lot, > clion > -- > View this message in context: > http://www.nabble.com/referring-to-data-of-previous-rows-tp25987364p25987364.html > Sent from the R help mailing list archive at Nabble.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. > ______________________________________________ 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.
