From ae31d3a7b54d1abdd99422d96b11e448f9835fd6 Mon Sep 17 00:00:00 2001
From: Christoph Ruegg <git@cdrnet.ch>
Date: Fri, 25 Nov 2016 15:37:33 +0100
Subject: [PATCH] LA: Vector MapInplace implemented at storage level

---
 .../Storage/DenseVectorStorage.cs             | 26 ++++++-
 .../Storage/SparseVectorStorage.cs            | 72 ++++++++++++++++++-
 .../LinearAlgebra/Storage/VectorStorage.cs    | 20 +++++-
 src/Numerics/LinearAlgebra/Vector.cs          | 12 ++--
 4 files changed, 119 insertions(+), 11 deletions(-)

diff --git a/src/Numerics/LinearAlgebra/Storage/DenseVectorStorage.cs b/src/Numerics/LinearAlgebra/Storage/DenseVectorStorage.cs
index f5ba1401..7d4d7b18 100644
--- a/src/Numerics/LinearAlgebra/Storage/DenseVectorStorage.cs
+++ b/src/Numerics/LinearAlgebra/Storage/DenseVectorStorage.cs
@@ -436,7 +436,29 @@ namespace MathNet.Numerics.LinearAlgebra.Storage
             return base.Find2Unchecked(other, predicate, zeros);
         }
 
-        // FUNCTIONAL COMBINATORS
+        // FUNCTIONAL COMBINATORS: MAP
+
+        public override void MapInplace(Func<T, T> f, Zeros zeros = Zeros.AllowSkip)
+        {
+            CommonParallel.For(0, Data.Length, 4096, (a, b) =>
+            {
+                for (int i = a; i < b; i++)
+                {
+                    Data[i] = f(Data[i]);
+                }
+            });
+        }
+
+        public override void MapIndexedInplace(Func<int, T, T> f, Zeros zeros = Zeros.AllowSkip)
+        {
+            CommonParallel.For(0, Data.Length, 4096, (a, b) =>
+            {
+                for (int i = a; i < b; i++)
+                {
+                    Data[i] = f(i, Data[i]);
+                }
+            });
+        }
 
         internal override void MapToUnchecked<TU>(VectorStorage<TU> target, Func<T, TU> f, Zeros zeros, ExistingData existingData)
         {
@@ -539,6 +561,8 @@ namespace MathNet.Numerics.LinearAlgebra.Storage
             base.Map2ToUnchecked(target, other, f, zeros, existingData);
         }
 
+        // FUNCTIONAL COMBINATORS: FOLD
+
         internal override TState Fold2Unchecked<TOther, TState>(VectorStorage<TOther> other, Func<TState, T, TOther, TState> f, TState state, Zeros zeros)
         {
             var denseOther = other as DenseVectorStorage<TOther>;
diff --git a/src/Numerics/LinearAlgebra/Storage/SparseVectorStorage.cs b/src/Numerics/LinearAlgebra/Storage/SparseVectorStorage.cs
index 0fe2baa4..226a8923 100644
--- a/src/Numerics/LinearAlgebra/Storage/SparseVectorStorage.cs
+++ b/src/Numerics/LinearAlgebra/Storage/SparseVectorStorage.cs
@@ -774,7 +774,75 @@ namespace MathNet.Numerics.LinearAlgebra.Storage
             return base.Find2Unchecked(other, predicate, zeros);
         }
 
-        // FUNCTIONAL COMBINATORS
+        // FUNCTIONAL COMBINATORS: MAP
+
+        public override void MapInplace(Func<T, T> f, Zeros zeros = Zeros.AllowSkip)
+        {
+            var indices = new List<int>();
+            var values = new List<T>(ValueCount);
+            if (zeros == Zeros.Include || !Zero.Equals(f(Zero)))
+            {
+                int k = 0;
+                for (int i = 0; i < Length; i++)
+                {
+                    var item = k < ValueCount && (Indices[k]) == i ? f(Values[k++]) : f(Zero);
+                    if (!Zero.Equals(item))
+                    {
+                        values.Add(item);
+                        indices.Add(i);
+                    }
+                }
+            }
+            else
+            {
+                for (int i = 0; i < ValueCount; i++)
+                {
+                    var item = f(Values[i]);
+                    if (!Zero.Equals(item))
+                    {
+                        values.Add(item);
+                        indices.Add(Indices[i]);
+                    }
+                }
+            }
+            Indices = indices.ToArray();
+            Values = values.ToArray();
+            ValueCount = values.Count;
+        }
+
+        public override void MapIndexedInplace(Func<int, T, T> f, Zeros zeros = Zeros.AllowSkip)
+        {
+            var indices = new List<int>();
+            var values = new List<T>(ValueCount);
+            if (zeros == Zeros.Include)
+            {
+                int k = 0;
+                for (int i = 0; i < Length; i++)
+                {
+                    var item = k < ValueCount && (Indices[k]) == i ? f(i, Values[k++]) : f(i, Zero);
+                    if (!Zero.Equals(item))
+                    {
+                        values.Add(item);
+                        indices.Add(i);
+                    }
+                }
+            }
+            else
+            {
+                for (int i = 0; i < ValueCount; i++)
+                {
+                    var item = f(Indices[i], Values[i]);
+                    if (!Zero.Equals(item))
+                    {
+                        values.Add(item);
+                        indices.Add(Indices[i]);
+                    }
+                }
+            }
+            Indices = indices.ToArray();
+            Values = values.ToArray();
+            ValueCount = values.Count;
+        }
 
         internal override void MapToUnchecked<TU>(VectorStorage<TU> target, Func<T, TU> f, Zeros zeros, ExistingData existingData)
         {
@@ -1074,6 +1142,8 @@ namespace MathNet.Numerics.LinearAlgebra.Storage
             base.Map2ToUnchecked(target, other, f, zeros, existingData);
         }
 
+        // FUNCTIONAL COMBINATORS: MAP
+
         internal override TState Fold2Unchecked<TOther, TState>(VectorStorage<TOther> other, Func<TState, T, TOther, TState> f, TState state, Zeros zeros)
         {
             var sparseOther = other as SparseVectorStorage<TOther>;
diff --git a/src/Numerics/LinearAlgebra/Storage/VectorStorage.cs b/src/Numerics/LinearAlgebra/Storage/VectorStorage.cs
index 913e72ab..b979b455 100644
--- a/src/Numerics/LinearAlgebra/Storage/VectorStorage.cs
+++ b/src/Numerics/LinearAlgebra/Storage/VectorStorage.cs
@@ -479,7 +479,23 @@ namespace MathNet.Numerics.LinearAlgebra.Storage
             return null;
         }
 
-        // FUNCTIONAL COMBINATORS
+        // FUNCTIONAL COMBINATORS: MAP
+
+        public virtual void MapInplace(Func<T, T> f, Zeros zeros = Zeros.AllowSkip)
+        {
+            for (int i = 0; i < Length; i++)
+            {
+                At(i, f(At(i)));
+            }
+        }
+
+        public virtual void MapIndexedInplace(Func<int, T, T> f, Zeros zeros = Zeros.AllowSkip)
+        {
+            for (int i = 0; i < Length; i++)
+            {
+                At(i, f(i, At(i)));
+            }
+        }
 
         public void MapTo<TU>(VectorStorage<TU> target, Func<T, TU> f,
             Zeros zeros = Zeros.AllowSkip, ExistingData existingData = ExistingData.Clear)
@@ -567,6 +583,8 @@ namespace MathNet.Numerics.LinearAlgebra.Storage
             }
         }
 
+        // FUNCTIONAL COMBINATORS: FOLD
+
         public TState Fold2<TOther, TState>(VectorStorage<TOther> other, Func<TState, T, TOther, TState> f, TState state, Zeros zeros = Zeros.AllowSkip)
             where TOther : struct, IEquatable<TOther>, IFormattable
         {
diff --git a/src/Numerics/LinearAlgebra/Vector.cs b/src/Numerics/LinearAlgebra/Vector.cs
index 7bd2a51d..21ab4a03 100644
--- a/src/Numerics/LinearAlgebra/Vector.cs
+++ b/src/Numerics/LinearAlgebra/Vector.cs
@@ -350,8 +350,7 @@ namespace MathNet.Numerics.LinearAlgebra
         /// </summary>
         public void MapInplace(Func<T, T> f, Zeros zeros = Zeros.AllowSkip)
         {
-            // TODO: actual in-place
-            Storage.MapToUnchecked(Storage, f, zeros, ExistingData.AssumeZeros);
+            Storage.MapInplace(f, zeros);
         }
 
         /// <summary>
@@ -362,8 +361,7 @@ namespace MathNet.Numerics.LinearAlgebra
         /// </summary>
         public void MapIndexedInplace(Func<int, T, T> f, Zeros zeros = Zeros.AllowSkip)
         {
-            // TODO: actual in-place
-            Storage.MapIndexedToUnchecked(Storage, f, zeros, ExistingData.AssumeZeros);
+            Storage.MapIndexedInplace(f, zeros);
         }
 
         /// <summary>
@@ -375,8 +373,7 @@ namespace MathNet.Numerics.LinearAlgebra
         {
             if (ReferenceEquals(this, result))
             {
-                // TODO: actual in-place
-                Storage.MapToUnchecked(Storage, f, zeros, ExistingData.AssumeZeros);
+                Storage.MapInplace(f, zeros);
             }
             else
             {
@@ -394,8 +391,7 @@ namespace MathNet.Numerics.LinearAlgebra
         {
             if (ReferenceEquals(this, result))
             {
-                // TODO: actual in-place
-                Storage.MapIndexedToUnchecked(Storage, f, zeros, ExistingData.AssumeZeros);
+                Storage.MapIndexedInplace(f, zeros);
             }
             else
             {