Im trying to store all the prime numbers in a vector into an object.
Q8.16 <-function(vector){ for(i in 1:length(vector)){ if (vector[i] == 2L || all(vector[i] %% 2L:ceiling(sqrt(vector[i])) != 0)){ prime1<-NULL prime1<-append(prime1,vector[i]) } } prime1 } sample1<-sample(1:1000 ,1000) Q8.16(sample1) The output I get from it is only one digit instead of a vector with all the prime numbers. Why is this happening?
If I'm understanding your intention correctly, it looks like the only change you need to make is move prime1<-NULL just before the for-loop. In your version of the code, you were resetting the list of primes every time you found a new one. The fixed version (with spacing tidied up) is below.
Q8.16 <- function(vector) { prime1 <- NULL # moved this outside the for-loop for (i in 1:length(vector)) { if (vector[i] == 2L || all(vector[i] %% 2L:ceiling(sqrt(vector[i])) != 0)) { prime1 <- append(prime1, vector[i]) } } prime1 } sample1 <- sample(1:1000, 1000) Q8.16(sample1) Testing it with sample1 <- 1:100 returns [1] 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97 which looks correct to me.
emptyvectoris never used, andreturnexits the function immediately when it finds the first prime number.