Round values to the nearest 0.05, 5, 10 etc.

round_nearest.R

# function to round a value to the nearest digit
# e.g. if nearest = 5 then 42 would round to 40
# and 47 would be rounded to 45
# source: http://r.789695.n4.nabble.com/Rounding-to-the-nearest-5-td863189.html

round_nearest <- function(x, nearest) {
  nearest * round(x / nearest)
}