Scaled Random Walk Approximation to BM
Purpose
Step function approximation to weiner
> library(sde) > par(mfrow = c(2, 2)) > T <- 100 > t <- 1/100 > main <- paste(" N =", T) > x <- seq(0, 1, t) > y <- c(0, (cumsum(rnorm(T)/sqrt(T)))) > plot(x, y, type = "s", main = main) > T <- 1000 > t <- 1/T > main <- paste(" N =", T) > x <- seq(0, 1, t) > y <- c(0, (cumsum(rnorm(T)/sqrt(T)))) > plot(x, y, type = "s", main = main) > T <- 10000 > t <- 1/T > main <- paste(" N =", T) > x <- seq(0, 1, t) > y <- c(0, (cumsum(rnorm(T)/sqrt(T)))) > plot(x, y, type = "s", , main = main) > x <- BM(N = T) > main <- "BM" > plot.ts(x, , main = main) |