how to avoid this loop in R (rapply ? lapply ?) -

i'm trying replace loop symple command without succes (lapply ? rapply ? mapply ?). maybe it's rare case in r loops needed ?

n <- 10 x <- vector(mode="numeric", length=n)  for(i in 2:n) {     x[i] <- x[i-1]+runif(1) } 

my question badly formulated. responses helped me understand need access values ​​of vector function. loop simple function "f" can calculated:

x <- c(1,2,3,4) for(i in 2:4) {     x[i] <- f(x[i-1]) } 

maybe way global variables ?

for exact question, don't need apply function @ all, because can vectorise cumsum:

your code:

n <- 10 x <- vector(mode="numeric", length=n)  set.seed(1) for(i in 2:n) {   x[i] <- x[i-1]+runif(1) } x [1] 0.0000000 0.2655087 0.6376326 1.2104859 2.1186937 2.3203756 3.2187653 4.1634406 4.8242384 [10] 5.4533524 

my code:

set.seed(1) c(0, cumsum(runif(n-1)))  [1] 0.0000000 0.2655087 0.6376326 1.2104859 2.1186937 2.3203756 3.2187653 4.1634406 4.8242384 [10] 5.4533524