My question is how to write a periodic function in R. for example if there is a function f(x) that f(x)=f(x+4), for -2<x<2, f(x)=x how to write it in R? thanks a lot! ------------------------------- liyun (Lauren) Ma
On 7/25/2005 11:22 AM, lma5 at ncsu.edu wrote:> My question is how to write a periodic function in R. > for example if there is a function f(x) that > f(x)=f(x+4), for -2<x<2, f(x)=x > how to write it in R? > thanks a lot!Just write a function that does that, e.g. f <- function(x) (x + 2) %% 4 - 2 The %% is the mod operator, so (x + 2) %% 4 adds 2 then maps all values into the range 0 to 4. You'll need a different formula for a different periodic function. Use plot(f, from=-7, to=7) to see that this works. Duncan Murdoch
On Mon, 25 Jul 2005 lma5 at ncsu.edu wrote:> My question is how to write a periodic function in R. > for example if there is a function f(x) that > f(x)=f(x+4), for -2<x<2, f(x)=x > how to write it in R?f((x+2)%%4 - 2) is one way. -- Brian D. Ripley, ripley at stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595