How to Round to the Nearest Tenth?

Question

Given any number of the sort 78.689 or 1.12 for instance, what I'm looking for is to programmatically round the number to the nearest tenth place after the decimal.

I'm trying to do this in an environment where there is a math.floor() function that rounds to the lowest whole number, and as far as I can tell from documentation there's nothing like PHP's round() function.

Answer 1

There's simple snippet at: http://lua-users.org/wiki/SimpleRound

function round(num, numDecimalPlaces)
  local mult = 10^(numDecimalPlaces or 0)
  return math.floor(num * mult + 0.5) / mult
end

It will misbehave when numDecimalPlaces is negative, but there's more examples on that page.