display <- function(a = 1, b = 2, c = 3) { results <- c(a, b, c) names(results) <- c("a", "b", "c") return(results) } display() display(c = 55, a = 5) best_practice <- c("Let", "the", "computer", "do", "the", "work") print_words <- function(sentence) { print(sentence[1]) print(sentence[2]) print(sentence[3]) print(sentence[4]) print(sentence[5]) print(sentence[6]) } print_words(best_practice) print_words(best_practice[-6]) print_words <- function(sentence) { for (word in sentence) { print(word) } } print_words(best_practice) print_words(best_practice[-6]) letter <- "z" for (letter in c("a", "b", "c")) { print(letter) } letter vowels <- c("a", "e", "i", "o", "u") len <- 0 for (apple in vowels) { len <- len + 1 } # Exponentiation exercise 2^4 expo <- function(base, power) { result <- 1 for (i in 1:power) { result <- result * base } return(result) } expo(2, 4) 6^5 expo(6, 5) print_N <- function(N) { nseq <- seq(N) for (onion in nseq) { print(onion) } } print_N(3) print_N(10) print_N <- function(N) { for(onion in 1:N) { print(onion) } } # create a function to sum numbers total <- function(vec) { vec_sum <- 0 for (num in vec) { print("vec_sum is") print(vec_sum) print("num is") print(num) vec_sum <- vec_sum + num } return(vec_sum) } total(vec = c(10, 2, -1)) total(c(100, 987, -87, 90)) sum(c(100, 987, -87, 90)) filenames <- list.files(path = "data", pattern = "inflammation", full.names = TRUE) for (f in filenames) { print(f) analyze(f) }