How to e.g. find the proportion of NAs in your data by column.
The old way is:
sapply(mydata, function (x) mean(is.na(x), na.rm = TRUE))
This wastes a lot of time typing out function(x) etc., and is hard to read.
Here's a better way, using the wonderful dplyr:
sapply(mydata, . %>% is.na %>% mean(na.rm = TRUE))
The magic is that the dot . before the pipe operator %>% creates a function.