# Floating Point Rounding

## Problem

You need to round a floating-point number to an integer.

## Solution

Use one of the functions round/1, ceiling/1, floor/1 and trunc/1. Note, the standard Erlang distribution does not come with either floor/1 or ceiling/1, but they can be easily implemented in terms of trunc/1

floor(X) -> T = trunc(X), case X - T < 0 of true -> T - 1; false -> T end. ceiling(X) -> T = trunc(X), case X - T < 0 of true -> T; false -> T + 1 end. 1> floor(-4.3). -5 2> ceiling(-4.3). -4 3> trunc(-4.3). -4 4> round(-4.3). -4 5> floor(3.5). 3 6> ceiling(3.5). 4 7> trunc(3.5). 3 8> round(3.5). 4 9> round(7). 7

The procedures all return integers.

round/1 returns the closest integer to x, rounding to even when x is halfway between two integers. floor/1 returns the largest integer not larger than x. ceiling/1 returns the smallest integer not smaller than x. trunc/1 returns the integer closest to x whose absolute value is not larger than the absolute value of x.

Further general information on math and rounding is available from:

MathWorld definition of the Floor Function. MathWorld definition of the Ceiling Function

blackjack hints online casino for cash casino games online free online casino tournament free online casino tournament internet casinos sites play casino games games online online casino tips casinos portal casinos games