What is the most useful R trick? [closed]

Answer 1

One of my favorite, if not somewhat unorthodox tricks, is the use of eval() and parse(). This example perhaps illustrates how it can be helpful

NY.Capital <- 'Albany'
state <- 'NY'
parameter <- 'Capital'
eval(parse(text=paste(state, parameter, sep='.')))

[1] "Albany"

This type of situation occurs more often than not, and use of eval() and parse() can help address it. Of course, I welcome any feedback on alternative ways of coding this up.