a good lapply() tutorial

Using lapply() to Change Multiple Dataframes with One Call

# a dataframe

a <- data.frame(x = 1:3, y = 4:6)

 

# make a list of several dataframes, then apply function (change column names, e.g.):

my.list <- list(a, a)

my.list <- lapply(my.list, function(x) {names(x) <- c("a", "b") ; return(x)})

 

# save dfs to csv with similar lapply-call:

n <- 1:length(my.list)

lapply(n, function(ni) {

               write.table(file = paste(c(1:length(my.list))[ni], ".csv", sep = ""), 

               my.list[ni], sep = ";", row.names = F)

               }

       )