[R] sequential sum

baccts baccts at hotmail.com
Tue Feb 14 18:04:23 CET 2012

Dear R users,

I am trying to sum number that exist in another vector up to i, then
increment i and repeat.
Sorry. It's hard to explain but basically I am trying to do the following:
test <- c(1,2,3,4);
test2 <- c(3,5,6,7,2,8,8,4,4);
test3 <- c(10,20,30,40);
tmp <- 0;
for (i in 1:length(test)){
tmp[i] <- sum(test3[which(test[1:i] %in% test2)]);

so when i = 1, tmp[i] = 0 because test[1]=1 is not in test2 and
when i = 3, tmp[i] = 50 = test3[2] + test3[3] because test[2:3] is in test2

Problem is test has 5000+ entries. How do I do the same thing without the

Thanks in advance. 

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