Apply Family - R Programming

Apply-style functions run one operation across pieces of data. sapply simplifies the result when it can.

Program

Play the script to sum each list element and select one named total.

apply_family.R

values <- list(a = 1:3, b = 4:5)
totals <- sapply(values, sum)
answer <- totals["b"]
cat(answer, "\n", sep = "")

list A list can hold vectors of different lengths under names.

sapply `sapply(values, sum)` runs `sum` for each list element.

named vector The result keeps names such as `a` and `b`.