A simple example of lapply

lapply_example.R

mydata1 <- data.frame(letter = c("a","b","c","a","b","c"))
mydata2 <- data.frame(letter = c("a","b","c","a","b","c","a","b","a"))
stuff <- list(mydata1,mydata2)


myawesome <- function(df) {
  levels <- c("a","b","c")
  as.factor(df$letter)
}

lapply(stuff, myawesome)

named_lists_example.R

mylist <- list(a=data.frame(vals=rnorm(100)),b=data.frame(vals=rnorm(100))  )

my_summary <- function(df) {
  stdev <- sd(df$vals)
  mean_val <- mean(df$vals)
  list(stdev=stdev, mean=mean_val)
}

lapply(mylist, my_summary)