Round values to nearest multiple's of {n} and/or to an arbitrary precision (number of decimals)

roundValue.php

<?php

/**
 * Created by: Lennart van den Dool <lennartvdd at gmail.com>
 */
Class SomeModel 
{
	/**
	 * @var integer The number of decimals to round to
	 * 
	 * Default: 2
	 */
	public $round_precision = 2;
	
	/**
	 * @var integer In which direction to perform the rounding:
	 * - -1: floor
	 * -  0: round
	 * -  1: ceil
	 * 
	 * Default: 0
	 */
	public $round_precision_direction = 0;
	
	/**
	 * @var integer @see round()'s $mode parameter (http://nl3.php.net/round). 
	 * 
	 * Default: PHP_ROUND_HALF_UP
	 */
	public $round_mode = PHP_ROUND_HALF_UP;
	
	/**
	 * @var integer Round to the nearest mutliple of {n}
	 */
	public $round_to_nearest_multiple;
	
	/**
	 * @var integer Round up, down or normal to the nearest multiple of {n}
	 * 
	 * Default: 0
	 */
	public $round_to_nearest_multiple_direction = 0;
	
	/**
	 * Rounds a value to an arbitrary precision, using the options specified above.
	 * - -1: round down (uses: floor()
	 * -  0: default (uses: round(), rounds halves up)
	 * -  1: round up (uses: ceil())
	 * 
	 * @param float $value
	 * @return float
	 */
	public function roundValue($value) {
  	
		if($this->round_to_nearest_multiple > 0) 
		{
			if($this->round_to_nearest_multiple_direction < 0) {
				//round down
				$value = floor($value * $this->round_to_nearest_multiple) / $this->round_to_nearest_multiple;
			} elseif($this->round_to_nearest_multiple_direction > 0) {
				//round up
				$value = ceil($value * $this->round_to_nearest_multiple) / $this->round_to_nearest_multiple;
			} else {
				//round normal
				$value = round($value * $this->round_to_nearest_multiple) / $this->round_to_nearest_multiple;
			}			
		}
		
		if($this->round_precision > 0) {
			$value = round($value, $this->round_precision, $this->round_mode);
		} 
		
		return $value;
	}
}