Vectorized Choices - R Programming

ifelse chooses values element by element. It avoids a loop when the same condition applies across a vector.

Program

Play the script to label three scores in one vectorized step.

ifelse_vector.R

scores <- c(92, 71, 84)
labels <- ifelse(scores >= 80, "pass", "retry")
summary <- paste(labels, collapse = ",")
cat(summary, "\n", sep = "")

ifelse `ifelse(test, yes, no)` chooses per position.

vectorized One expression operates across the whole vector.

logical vector `scores >= 80` supplies one `TRUE` or `FALSE` per score.