Array.prototype.min = function()
{
	if (this.length > 0)
	{
		var value = this[0];
		for (var i = 1; i < this.length; i++)
		{
			if (value > this[i]) value = this[i];
		}
		return value - 0;
	}
	else
	{
		return 0;
	}
}

Array.prototype.max = function()
{
	if (this.length > 0)
	{
		var value = this[0];
		for (var i = 1; i < this.length; i++)
		{
			if (value < this[i]) value = this[i];
		}
		return value - 0;
	}
	else
	{
		return 0;
	}
}

Array.prototype.getEach = function(position, start)
{
	var ary_values = new Array();
	for (var i = start; i < this.length; i = i + position)
	{
		ary_values.push(this[i]);
	}
	return ary_values;
}

Array.prototype.normalize = function()
{
	minvalue = this.min();
	var ary_values = new Array();
	for (var i = 0; i < this.length; i++)
	{
		ary_values.push(this[i] - minvalue);
	}
	return ary_values;
}