Changeset 11309 for trunk/sources

Timestamp:

08/27/14 10:14:54 (10 years ago)

Author:

bburlacu

Message:

#2234: Added CartesianProduct extension method to HeuristicLab.Common/3.3/EnumerableExtensions.cs, used to generate all possible combinations of parameters for the grid search.

File:

• trunk/sources/HeuristicLab.Common/3.3/EnumerableExtensions.cs (modified) (1 diff)

trunk/sources/HeuristicLab.Common/3.3/EnumerableExtensions.cs

@@ -87 +87 @@
       return result;
     }
+
+    /// <summary>
+    /// Compute the n-ary cartesian product of arbitrarily many sequences: http://blogs.msdn.com/b/ericlippert/archive/2010/06/28/computing-a-cartesian-product-with-linq.aspx
+    /// </summary>
+    /// <typeparam name="T">The type of the elements inside each sequence</typeparam>
+    /// <param name="sequences">The collection of sequences</param>
+    /// <returns>An enumerable sequence of all the possible combinations of elements</returns>
+    public static IEnumerable<IEnumerable<T>> CartesianProduct<T>(this IEnumerable<IEnumerable<T>> sequences) {
+      IEnumerable<IEnumerable<T>> result = new[] { Enumerable.Empty<T>() };
+      return sequences.Aggregate(result, (current, s) => (from seq in current from item in s select seq.Concat(new[] { item })));
+    }
   }
 }