I would like to know whether there is a faster way to do the below operation (updating vec1).
My objective is to update the elements of a vector (vec1), where a particular element i is dependent on the previous one. I need to do this on vectors that are 1 million or longer and need to repeat that process several hundred times. The for loop works but is slow. If there is a faster way, please let me know. probs <- c(.1, .3, .2, .4, .7, .9, .3, .4, .5, .6) p10 <- 0.6 p00 <- 0.4 vec1 <- rep(0, 10) for (i in 2:10) { vec1[i] <- ifelse(vec1[i-1] == 0, ifelse(probs[i]<p10, 0, 1), ifelse(probs[i]<p00, 0, 1)) } Thanks GG [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.