LA: Vectors: delegate GetHashCode fully to storage

src/Numerics/LinearAlgebra/Complex/SparseVector.cs

@@ -1103,28 +1103,6 @@ namespace MathNet.Numerics.LinearAlgebra.Complex
             return base.ToString(format, formatProvider);
         }
 
-        /// <summary>
-        /// Returns a hash code for this instance.
-        /// </summary>
-        /// <returns>
-        /// A hash code for this instance, suitable for use in hashing algorithms and data structures like a hash table. 
-        /// </returns>
-        public override int GetHashCode()
-        {
-            var hashNum = Math.Min(_storage.ValueCount, 20);
-            long hash = 0;
-            for (var i = 0; i < hashNum; i++)
-            {
-#if PORTABLE
-                hash ^= Precision.DoubleToInt64Bits(_storage.Values[i].GetHashCode());
-#else
-                hash ^= BitConverter.DoubleToInt64Bits(_storage.Values[i].GetHashCode());
-#endif
-            }
-
-            return BitConverter.ToInt32(BitConverter.GetBytes(hash), 4);
-        }
-
         #endregion
 
         /// <summary>

src/Numerics/LinearAlgebra/Complex32/SparseVector.cs

@@ -1103,28 +1103,6 @@ namespace MathNet.Numerics.LinearAlgebra.Complex32
             return base.ToString(format, formatProvider);
         }
 
-        /// <summary>
-        /// Returns a hash code for this instance.
-        /// </summary>
-        /// <returns>
-        /// A hash code for this instance, suitable for use in hashing algorithms and data structures like a hash table. 
-        /// </returns>
-        public override int GetHashCode()
-        {
-            var hashNum = Math.Min(_storage.ValueCount, 20);
-            long hash = 0;
-            for (var i = 0; i < hashNum; i++)
-            {
-#if PORTABLE
-                hash ^= Precision.DoubleToInt64Bits(_storage.Values[i].GetHashCode());
-#else
-                hash ^= BitConverter.DoubleToInt64Bits(_storage.Values[i].GetHashCode());
-#endif
-            }
-
-            return BitConverter.ToInt32(BitConverter.GetBytes(hash), 4);
-        }
-
         #endregion
 
         /// <summary>

src/Numerics/LinearAlgebra/Double/SparseVector.cs

@@ -1166,28 +1166,6 @@ namespace MathNet.Numerics.LinearAlgebra.Double
             return base.ToString(format, formatProvider);
         }
 
-        /// <summary>
-        /// Returns a hash code for this instance.
-        /// </summary>
-        /// <returns>
-        /// A hash code for this instance, suitable for use in hashing algorithms and data structures like a hash table. 
-        /// </returns>
-        public override int GetHashCode()
-        {
-            var hashNum = Math.Min(_storage.ValueCount, 20);
-            long hash = 0;
-            for (var i = 0; i < hashNum; i++)
-            {
-#if PORTABLE
-                hash ^= Precision.DoubleToInt64Bits(_storage.Values[i].GetHashCode());
-#else
-                hash ^= BitConverter.DoubleToInt64Bits(_storage.Values[i].GetHashCode());
-#endif
-            }
-
-            return BitConverter.ToInt32(BitConverter.GetBytes(hash), 4);
-        }
-
         #endregion
 
         /// <summary>

src/Numerics/LinearAlgebra/Generic/Vector.BCL.cs

@@ -63,7 +63,7 @@ namespace MathNet.Numerics.LinearAlgebra.Generic
         /// <returns>
         ///     <c>true</c> if the specified <see cref="System.Object"/> is equal to this instance; otherwise, <c>false</c>.
         /// </returns>
-        public override bool Equals(object obj)
+        public override sealed bool Equals(object obj)
         {
             var other = obj as Vector<T>;
             return other != null && Storage.Equals(other.Storage);
@@ -75,7 +75,7 @@ namespace MathNet.Numerics.LinearAlgebra.Generic
         /// <returns>
         /// A hash code for this instance, suitable for use in hashing algorithms and data structures like a hash table. 
         /// </returns>
-        public override int GetHashCode()
+        public override sealed int GetHashCode()
         {
             return Storage.GetHashCode();
         }

src/Numerics/LinearAlgebra/Single/SparseVector.cs

@@ -1164,28 +1164,6 @@ namespace MathNet.Numerics.LinearAlgebra.Single
             return base.ToString(format, formatProvider);
         }
 
-        /// <summary>
-        /// Returns a hash code for this instance.
-        /// </summary>
-        /// <returns>
-        /// A hash code for this instance, suitable for use in hashing algorithms and data structures like a hash table. 
-        /// </returns>
-        public override int GetHashCode()
-        {
-            var hashNum = Math.Min(_storage.ValueCount, 20);
-            long hash = 0;
-            for (var i = 0; i < hashNum; i++)
-            {
-#if PORTABLE
-                hash ^= Precision.DoubleToInt64Bits(_storage.Values[i].GetHashCode());
-#else
-                hash ^= BitConverter.DoubleToInt64Bits(_storage.Values[i].GetHashCode());
-#endif
-            }
-
-            return BitConverter.ToInt32(BitConverter.GetBytes(hash), 4);
-        }
-
         #endregion
 
         /// <summary>

src/Numerics/LinearAlgebra/Storage/SparseVectorStorage.cs

@@ -233,6 +233,27 @@ namespace MathNet.Numerics.LinearAlgebra.Storage
             return true;
         }
 
+        /// <summary>
+        /// Returns a hash code for this instance.
+        /// </summary>
+        /// <returns>
+        /// A hash code for this instance, suitable for use in hashing algorithms and data structures like a hash table. 
+        /// </returns>
+        public override int GetHashCode()
+        {
+            var values = Values;
+            var hashNum = Math.Min(ValueCount, 25);
+            int hash = 17;
+            unchecked
+            {
+                for (var i = 0; i < hashNum; i++)
+                {
+                    hash = hash * 31 + values[i].GetHashCode();
+                }
+            }
+            return hash;
+        }
+
         internal override void CopyToUnchecked(VectorStorage<T> target, bool skipClearing = false)
         {
             var sparseTarget = target as SparseVectorStorage<T>;