R has a lot of under-appreciated super powerful functions. I list a few of our favorites below.
Atlas, carrying the sky. Royal Palace (Paleis op de Dam), Amsterdam.
Photo: Dominik Bartsch, CC some rights reserved.
stats::approx(): approximate a curve/function.
base::cumsum(): cumulative ordered sum.
stats::ecdf(): estimate the cumulative distribution function.
base::findInterval(): assign values to bins.
base::match(): bulk computation of first match. Can lookup and sort data and even find non-duplicate data.
base::Reduce(): nifty functional method to combine multiple function evaluations.
base::tapply(): grouped summary function.
base::unlist(): build arrays of atomic values from more complicated nested structures.
base::Vectorize(): Convert scalar functions into functions ready to operate on arrays.
We would love to hear about some of your favorites.
Data Scientist and trainer at Win Vector LLC. One of the authors of Practical Data Science with R.