HI,
You could try this:
set.seed(112)
list1<-vector("list",1000)
for(i in 1:1000){
?list1[[i]]<-sample(c(-1,1),40,replace=TRUE)}
?dat1<-do.call(rbind,lapply(list1,function(x) sum(x)))
dat2<-matrix(dat1,ncol=20,byrow=TRUE)
head(dat2)
?# ?? [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [,11] [,12] [,13] [,14]
#[1,]?? -2?? 12??? 0??? 8??? 0??? 4?? -8??? 2?? -8??? -4?? -14???? 8??? -4?? -12
#[2,]??? 8??? 4?? -4??? 4?? 12?? -2?? -6??? 0?? -8???? 8??? -8??? 12???? 2???? 2
#[3,]?? -2??? 8??? 2?? -6? -12?? -6??? 8??? 6?? -4???? 4???? 4???? 8???? 6??? 10
#[4,]??? 6??? 6??? 0??? 4?? 10?? -8?? -4?? -2??? 4?? -10??? -6??? -2???? 4???? 2
#[5,]?? -6?? -4?? -6?? -6??? 4??? 0? -14?? -2??? 0??? -8??? -6???? 2???? 4??? -8
#[6,]??? 0?? 10??? 0??? 0? -14?? -2??? 2??? 0??? 6?? -10???? 4???? 0??? -4???? 4
? # ? [,15] [,16] [,17] [,18] [,19] [,20]
#[1,]???? 4??? 12??? -6???? 4??? 10???? 8
#[2,]??? -6???? 0???? 4???? 8???? 0??? 12
#[3,]??? -2??? -4??? 10?? -10???? 6?? -10
#[4,]???? 2???? 6???? 4???? 6???? 8???? 6
#[5,]??? 10???? 0??? -6??? -2??? 10??? -8
#[6,]???? 0?? -12??? 16??? -2???? 2???? 4
#system time for 10,000 times
system.time({
?set.seed(112)
?list1<-vector("list",10000)
?for(i in 1:10000){
? list1[[i]]<-sample(c(-1,1),40,replace=TRUE)}
? dat1<-do.call(rbind,lapply(list1,function(x) sum(x)))
?dat2<-matrix(dat1,ncol=200,byrow=TRUE)
?})
?? user? system elapsed
? 0.112?? 0.000?? 0.111
A.K.
----- Original Message -----
From: darnold <dwarnold45 at suddenlink.net>
To: r-help at r-project.org
Cc:
Sent: Friday, August 3, 2012 10:14 PM
Subject: Re: [R] Head or Tails game
David,
set.seed(123)? # always good to make reproducible
winnings <- sum(sample(c(-1,1), 10000, replace=TRUE))
Unfortunately, that's not the game. The game requires 40 flips of a coin.
Then you have to play the game 10,000 times.
D.
--
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