Initial Commit

Common/Auxiliary/DataSearch/SortedXSearcher1d.cs

@@ -0,0 +1,56 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Windows;
+
+namespace Microsoft.Research.DynamicDataDisplay.Common.DataSearch
+{
+	internal class SortedXSearcher1d
+	{
+		private readonly IList<Point> collection;
+		public SortedXSearcher1d(IList<Point> collection)
+		{
+			if (collection == null)
+				throw new ArgumentNullException("collection");
+
+			this.collection = collection;
+		}
+
+		public SearchResult1d SearchXBetween(double x)
+		{
+			return SearchXBetween(x, SearchResult1d.Empty);
+		}
+
+		public SearchResult1d SearchXBetween(double x, SearchResult1d result)
+		{
+			if (collection.Count == 0)
+				return SearchResult1d.Empty;
+
+			int lastIndex = collection.Count - 1;
+
+			if (x < collection[0].X)
+				return SearchResult1d.Empty;
+			else if (collection[lastIndex].X < x)
+				return SearchResult1d.Empty;
+
+			int startIndex = !result.IsEmpty ? Math.Min(result.Index, lastIndex) : 0;
+
+			// searching ascending
+			if (collection[startIndex].X < x)
+			{
+				for (int i = startIndex + 1; i <= lastIndex; i++)
+					if (collection[i].X >= x)
+						return new SearchResult1d { Index = i - 1 };
+			}
+			else // searching descending
+			{
+				for (int i = startIndex - 1; i >= 0; i--)
+					if (collection[i].X <= x)
+						return new SearchResult1d { Index = i };
+			}
+
+			throw new InvalidOperationException("Should not appear here.");
+		}
+	}
+}