how to speed up the process of R

Hi,

Compare this:

a<-list()
system.time(for(i in 1:100000){
a[[i]]<-i*1000
})

system.time(a2 <- as.vector(1000 * (1:100000), "list"))
all.equal(a, a2)

## > system.time(for(i in 1:100000){
## + a[[i]]<-i*1000
## + })
##    user  system elapsed
##   28.66    0.02   28.84
## > system.time(a2 <- as.vector(1000 * (1:100000), "list"))
##    user  system elapsed
##       0       0       0
## > all.equal(a, a2)
## [1] TRUE

Cheers,

Josh

hi
?I'm simulating some experiment by "for" function.
The problem is that it takes too much time.

for example,

a<-list()

for(i in 1:100000000){
a[[i]]<-i*1000
}

is there anyway to speed up the process?
I heard there is solution but i don't have idea.

Can anyone help me?

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Joshua Wiley
Ph.D. Student, Health Psychology
Programmer Analyst II, Statistical Consulting Group
University of California, Los Angeles
https://joshuawiley.com/