How to create function of tossing coin R

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I'm trying to create a function in R to simulate the experiment of tossing four coins as many times as m times, each experiment records the appearance of "numbers" or "images" on each coin.
Present the results of m experiments in tabular form, and add the "number of sides of the number that appears" in the last column of the table.

Sim_Coin<-function(m){
c1<-c()
c2<-c()
cs<-c()
for(i in 1:m)
{
c1<-rbind(d1,sample(0:1,size=1)
c2<-rbind(d2,sample(0:1,size=1)
}
cs<-c1+c2
v<-cbind(c1,c2,cs)
v<-as.data.frame(v)
names(v)<-c("coin1","coin2","sum")
return(v)
}

But it fails and I don't know how to create the table

probability r sorting arrays
1 Answers

R is a vectorized language so in many cases the need for a loop can be avoided. So instead of looping m times, just pick m samples from 0 or 1. This will greatly improve performance.

Also progressively adding onto a vector or data frame with bind function, inside a loop, is slow in R since a new copy of the information is created with each function call.

Take a look at this streamline code:

Sim_Coin<-function(m){
  coin1<-sample(c("head", "tail"), size=m, replace=TRUE)
  coin2<-sample(c("head", "tail"), size=m, replace=TRUE)

  v<-data.frame(coin1, coin2)
  v$sum <- apply(v, 1, function(i){sum(i=="head")})
  return(v)
}

Sim_Coin(3)
  coin1 coin2 sum
1  tail  tail   0
2  head  head   2
3  tail  head   1

Since your question talked about flipping 4 coins and not just 2, here is an expanded version:

Sim_Coin2<-function(m){
  n<-4. #number of coins to flip

  #create n vectors m long
  coins<- lapply(1:n, function(i) {
    sample(0:1, size=m, replace=TRUE)
  })
  #make data frame and rename columns
  dfcoin<-as.data.frame(do.call(cbind, coins))
  names(dfcoin)<-paste0("Coin", 1:n)

  #calculate the number of heads by taking the sum of the rows
  dfcoin$sum <- rowSums(dfcoin)
  dfcoin
}

Sim_Coin2(10)
user_57922440
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