Changeset 11868 for stable/HeuristicLab.Problems.Instances.DataAnalysis/3.3/Regression/ValueGenerator.cs

Timestamp:

02/03/15 14:00:39 (9 years ago)

Author:

mkommend

Message:

#2259: Merged r11434, r11435, r11441 and r11313, r11348 into stable.

Location:

stable

Files:

• . (modified) (1 prop)
• HeuristicLab.Problems.Instances.DataAnalysis (modified) (1 prop)
• HeuristicLab.Problems.Instances.DataAnalysis/3.3/Regression/ValueGenerator.cs (modified) (1 diff)

stable/HeuristicLab.Problems.Instances.DataAnalysis/3.3/Regression/ValueGenerator.cs

@@ -31 +31 @@
 
     /// <summary>
-    /// Generates a sequence of evenly spaced points between start and end (inclusive!).
+    /// Generates a sequence of evenly spaced points by returning the start value and adding the stepwidth until the end is reached or surpassed.
+    /// 
     /// </summary>
     /// <param name="start">The smallest and first value of the sequence.</param>
     /// <param name="end">The largest and last value of the sequence.</param>
     /// <param name="stepWidth">The step size between subsequent values.</param>
-    /// <returns>An sequence of values from start to end (inclusive)</returns>
-    public static IEnumerable<double> GenerateSteps(double start, double end, double stepWidth) {
-      if (start > end) throw new ArgumentException("start must be less than or equal end.");
-      if (stepWidth <= 0) throw new ArgumentException("stepwith must be larger than zero.", "stepWidth");
-      double x = start;
-      // x<=end could skip the last value because of numerical problems
-      while (x < end || x.IsAlmost(end)) {
+    /// <param name="includeEnd">Determines if the end should be included in the sequence regardless if the end is divisible by the stepwidth.</param>
+    /// <returns>A sequence of values from start to end (inclusive)</returns>
+    [Obsolete("It is recommended to use the decimal overload to achieve a higher numerical accuracy.")] 
+    public static IEnumerable<double> GenerateSteps(double start, double end, double stepWidth, bool includeEnd = false) {
+      //mkommend: IEnumerable.Cast fails due to boxing and unboxing of the involved types
+      // http://referencesource.microsoft.com/#System.Core/System/Linq/Enumerable.cs#27bb217a6d5457ec
+      // http://blogs.msdn.com/b/ericlippert/archive/2009/03/19/representation-and-identity.aspx     
+
+      return GenerateSteps((decimal)start, (decimal)end, (decimal)stepWidth, includeEnd).Select(x => (double)x);
+    }
+
+    /// <summary>
+    /// Generates a sequence of evenly spaced points by returning the start value and adding the stepwidth until the end is reached or surpassed.
+    /// </summary>
+    /// <param name="start">The smallest and first value of the sequence.</param>
+    /// <param name="end">The largest and last value of the sequence.</param>
+    /// <param name="stepWidth">The step size between subsequent values.</param>
+    /// /// <param name="includeEnd">Determines if the end should be included in the sequence regardless if the end is divisible by the stepwidth.</param>
+    /// <returns>A sequence of values from start to end</returns>
+    public static IEnumerable<decimal> GenerateSteps(decimal start, decimal end, decimal stepWidth, bool includeEnd = false) {
+      if (stepWidth == 0)
+        throw new ArgumentException("The step width cannot be zero.");
+      if (start < end && stepWidth < 0)
+        throw new ArgumentException("The step width must be larger than zero for increasing sequences (start < end).");
+      if (start > end && stepWidth > 0)
+        throw new ArgumentException("The step width must be smaller than zero for decreasing sequences (start > end).");
+
+      decimal x = start;
+      while (x <= end) {
         yield return x;
         x += stepWidth;
       }
+      if (x - stepWidth < end && includeEnd) yield return end;
     }