Error for using for-loop when producing simulations - r

Question

I'm trying to use for loop to simulate 1,000 portfolios with 3 bonds in each portfolio, and finding the probability that two out of three bonds default.
Here's my code (with comments):
#Reproducibility
set.seed(33)
#Number of trials
n<-1000
#Initialize variables
numberofdefaults<-0
counter<-0
portfolio <- 0
for (i in 1:n){
portfolio[i] <- rbinom(3, 1, prob = 0.127) # generate three random binomial deviates with probabiltiy of sucess("default" in my case)0.127 and store them in a vector
numberofdefaults[i] <- sum(portfolio[i] == 1) # find the number of defaults in the vector (1 for default) and add them up
if (numberofdefaults[i] == 2) { # if number of defaults is 2, then add 1 to the counter
counter<-counter+1
}
}
When I execute the code, I keep getting an error message: number of items to replace is not a multiple of replacement length
Thnx so much for taking your time. Any suggestions would be appreciated.

Answer 1

Your code is not working as intended. Portfolio is a vector, so when you run rbinom(), which has 3 elements, you are attempting to cram 3 elements into one element (the ith element of that particular for loop). It gives you a warning that it can't do that (and only stores in the first element each time). Instead you want Portfolio to be a list.
set.seed(33)
#Number of trials
n<-1000
#Initialize variables
numberofdefaults<-0
counter<-0
portfolio <- list() # Change this
for (i in 1:n){
portfolio[[i]] <- rbinom(3, 1, prob = 0.127) # Change this
numberofdefaults[i] <- sum(portfolio[[i]] == 1) # Change this
if (numberofdefaults[i] == 2) {
counter<-counter+1
}
}