How about adding an additional argument to fun? R> fun <- function(x, y) exp(-x)*sum(y^x) R> y <- c(2,3,5) R> integrate(fun, 0, 3, y) [1] 346.853 with absolute error < 3.9e-12 Michael
On Tue, Oct 18, 2011 at 10:01 AM, Freddy Hernandez Barajas <fhern...@gmail.com> wrote: > Hello all R users > > I want to calculate this univariate integral: > exp(-x)*sum(y^x) respect to x from 0 to 3 where y is a vector y=(2,3,5). > In fact, the original y vector has a large number of elements but I propose > with 3 elements. > > I know that I can resolve this problem doing > > fun <- function(x) exp(-x)*(2^x+3^x+5^x) > integrate(fun,0,3) > > When the y vector has a large number of elements the last solution is not > possible, > if I use this another way I can not obtain the true answer > > y <- c(2,3,5) > fun1 <- function(x) exp(-x)*sum(y^x) > integrate(fun1,0,3) > > Someone could give me a help with the problem? > Thanks. > > > Freddy Hernández Barajas > > [[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. > > ______________________________________________ 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.
