changeset 34:d597feec5dd4

Closes #20 - Add rounding method with enum * Add RoundType enumeration with up, down, 'banker', up to half, down to half, 'banker' to half * Add IBBMath.Round(double, RoundType)
author IBBoard <dev@ibboard.co.uk>
date Tue, 19 May 2009 14:24:00 +0000
parents 8971a1c48dbf
children 2b5e73cb83a3
files Lang/IBBMath.cs
diffstat 1 files changed, 61 insertions(+), 0 deletions(-) [+]
line wrap: on
line diff
--- a/Lang/IBBMath.cs	Sun May 17 19:22:53 2009 +0000
+++ b/Lang/IBBMath.cs	Tue May 19 14:24:00 2009 +0000
@@ -7,6 +7,24 @@
 
 namespace IBBoard.Lang
 {
+	/// <summary>
+	/// RoundType defines how a number should be rounded. "Up" always rounds up (Ceiling), "Down" always rounds down (Floor), "Banker" rounds
+	/// up or down as appropriate with a balanced bias (rounding towards even). Each rounding method also has a "ToHalf" version that performs
+	/// the same type of rounding, but to the closes half number instead of the closest whole number.
+	/// </summary>
+	public enum RoundType
+	{
+		Up,
+		Down,
+		Banker,
+		UpToHalf,
+		DownToHalf,
+		BankerToHalf
+	}
+
+	/// <summary>
+	/// IBBMath provides a number of custom Maths functions based on the core Math classes.
+	/// </summary>
 	public class IBBMath
 	{
 		/// <summary>
@@ -51,5 +69,48 @@
 		{
 			return Math.Ceiling(number * 2) / 2;
 		}
+
+		/// <summary>
+		/// Returns the number rounded as defined by the <code>roundType</code>
+		/// </summary>
+		/// <param name="number">
+		/// The <see cref="System.Double"/> to round
+		/// </param>
+		/// <param name="roundType">
+		/// The way in which <code>number</code> should be rounded
+		/// </param>
+		/// <returns>
+		/// The rounded <see cref="System.Double"/>
+		/// </returns>
+		public static double Round(double number, RoundType roundType)
+		{
+			double val;
+			
+			switch (roundType)
+			{
+			case RoundType.Up:
+				val = Math.Ceiling(number);
+				break;
+			case RoundType.Down:
+				val = Math.Floor(number);
+				break;
+			case RoundType.Banker:
+				val = Math.Round(number);
+				break;
+			case RoundType.UpToHalf:
+				val = CeilToHalf(number);
+				break;
+			case RoundType.DownToHalf:
+				val = FloorToHalf(number);
+				break;
+			case RoundType.BankerToHalf:
+				val = RoundToHalf(number);
+				break;
+			default:
+				throw new InvalidOperationException("Unhandled round type: "+roundType);
+			}
+
+			return val;
+		}
 	}
 }