Your question is unclear. If the calculation of B[3] now depends on the newly calculated value of B[2], then the answer is no: you must loop. If B[3] is based on the original B[2] value, then the answer is yes, and the solution is just a matter of simple indexing, which I leave as an exercise.
-- Bert On Fri, Aug 27, 2010 at 10:17 AM, Marcus Drescher <dresc...@tum.de> wrote: > Hi all, > > I want to calculate in each row a ratio based on number in the current row > and the previous row. > Is there a way to do this without for-loops because that is extremely slow. > > A B > [1] 2 2 > [2] 2 3 > [3] 4 5,5 > ... > > B2 = A2 + 0.5*B1 > > > Thanks in advance. > Best > Marcus > > ______________________________________________ > 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<http://www.r-project.org/posting-guide.html> > and provide commented, minimal, self-contained, reproducible code. > [[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.
