all<-    list.files("C:\Users\dell\Desktop\KuiTunNDVI\KuiTunNDVI",full.names = TRUE, pattern = "*.tif")         `
fn <- list.files("C:\Users\dell\Desktop\KuiTunNDVI\KuiTunNDVI", full.names = FALSE, pattern = "*.tif")
r <- stack(all)
r<- brick(r)
g<-cellStats(r, stat='mean')
r.ts <- ts(g, start=c(2000,1), end=c(2001,1), frequency=1)
plot(r.ts)
h<-hurstexp(r.ts)$Hs