Added matrix indexed enumerator

src/Numerics/LinearAlgebra/Complex/SparseMatrix.cs

@@ -31,16 +31,17 @@
 namespace MathNet.Numerics.LinearAlgebra.Complex
 {
     using System;
+    using System.Collections.Generic;
     using System.Numerics;
     using Generic;
     using Properties;
     using Threading;
-    
+
     /// <summary>
     /// A Matrix class with sparse storage. The underlying storage scheme is 3-array compressed-sparse-row (CSR) Format.
     /// <a href="http://en.wikipedia.org/wiki/Sparse_matrix#Compressed_sparse_row_.28CSR_or_CRS.29">Wikipedia - CSR</a>.
     /// </summary>
-    public class SparseMatrix : Matrix 
+    public class SparseMatrix : Matrix
     {
         /// <summary>
         /// Object for use in "lock"
@@ -58,7 +59,7 @@ namespace MathNet.Numerics.LinearAlgebra.Complex
         /// array using the row-major storage mapping described in a compressed sparse row (CSR) format.
         /// </summary>
         private Complex[] _nonZeroValues = new Complex[0];
-        
+
         /// <summary>
         /// Gets the number of non zero elements in the matrix.
         /// </summary>
@@ -68,7 +69,7 @@ namespace MathNet.Numerics.LinearAlgebra.Complex
             get;
             private set;
         }
-        
+
         /// <summary>
         /// An array containing the column indices of the non-zero values. Element "I" of the array 
         /// is the number of the column in matrix that contains the I-th value in the <see cref="_nonZeroValues"/> array.
@@ -84,11 +85,12 @@ namespace MathNet.Numerics.LinearAlgebra.Complex
         /// <param name="columns">
         /// The number of columns.
         /// </param>
-        public SparseMatrix(int rows, int columns) : base(rows, columns)
+        public SparseMatrix(int rows, int columns)
+            : base(rows, columns)
         {
             _rowIndex = new int[rows];
         }
-        
+
         /// <summary>
         /// Initializes a new instance of the <see cref="SparseMatrix"/> class. This matrix is square with a given size.
         /// </summary>
@@ -96,7 +98,8 @@ namespace MathNet.Numerics.LinearAlgebra.Complex
         /// <exception cref="ArgumentException">
         /// If <paramref name="order"/> is less than one.
         /// </exception>
-        public SparseMatrix(int order) : this(order, order)
+        public SparseMatrix(int order)
+            : this(order, order)
         {
         }
 
@@ -110,7 +113,8 @@ namespace MathNet.Numerics.LinearAlgebra.Complex
         /// The number of columns.
         /// </param>
         /// <param name="value">The value which we assign to each element of the matrix.</param>
-        public SparseMatrix(int rows, int columns, Complex value) : this(rows, columns)
+        public SparseMatrix(int rows, int columns, Complex value)
+            : this(rows, columns)
         {
             if (value == 0.0)
             {
@@ -132,7 +136,7 @@ namespace MathNet.Numerics.LinearAlgebra.Complex
                 _nonZeroValues[i] = value;
                 _columnIndices[i] = j;
             }
-            
+
             // Set proper row pointers
             for (var i = 0; i < _rowIndex.Length; i++)
             {
@@ -148,7 +152,8 @@ namespace MathNet.Numerics.LinearAlgebra.Complex
         /// <param name="array">The one dimensional array to create this matrix from. This array should store the matrix in column-major order. see: http://en.wikipedia.org/wiki/Column-major_order </param>
         /// <exception cref="ArgumentOutOfRangeException">If <paramref name="array"/> length is less than <paramref name="rows"/> * <paramref name="columns"/>.
         /// </exception>
-        public SparseMatrix(int rows, int columns, Complex[] array) : this(rows, columns)
+        public SparseMatrix(int rows, int columns, Complex[] array)
+            : this(rows, columns)
         {
             if (rows * columns > array.Length)
             {
@@ -168,7 +173,8 @@ namespace MathNet.Numerics.LinearAlgebra.Complex
         /// Initializes a new instance of the <see cref="SparseMatrix"/> class from a 2D array. 
         /// </summary>
         /// <param name="array">The 2D array to create this matrix from.</param>
-        public SparseMatrix(Complex[,] array) : this(array.GetLength(0), array.GetLength(1))
+        public SparseMatrix(Complex[,] array)
+            : this(array.GetLength(0), array.GetLength(1))
         {
             var rows = array.GetLength(0);
             var columns = array.GetLength(1);
@@ -577,7 +583,7 @@ namespace MathNet.Numerics.LinearAlgebra.Complex
                 return index >= 0 ? _nonZeroValues[index] : 0.0;
             }
         }
-        
+
         /// <summary>
         /// Sets the value of the given element.
         /// </summary>
@@ -682,7 +688,7 @@ namespace MathNet.Numerics.LinearAlgebra.Complex
                 _nonZeroValues[i - 1] = _nonZeroValues[i];
                 _columnIndices[i - 1] = _columnIndices[i];
             }
-            
+
             // Decrease value in Row
             for (var i = row + 1; i < _rowIndex.Length; i++)
             {
@@ -699,7 +705,7 @@ namespace MathNet.Numerics.LinearAlgebra.Complex
                 Array.Resize(ref _columnIndices, NonZerosCount);
             }
         }
-        
+
         /// <summary>
         /// Find item Index in nonZeroValues array
         /// </summary>
@@ -714,7 +720,7 @@ namespace MathNet.Numerics.LinearAlgebra.Complex
             var endIndex = row < _rowIndex.Length - 1 ? _rowIndex[row + 1] : NonZerosCount;
             return Array.BinarySearch(_columnIndices, startIndex, endIndex - startIndex, column);
         }
-        
+
         /// <summary>
         /// Calculates the amount with which to grow the storage array's if they need to be
         /// increased in size.
@@ -794,7 +800,7 @@ namespace MathNet.Numerics.LinearAlgebra.Complex
                 Array.Copy(_rowIndex, sparseTarget._rowIndex, RowCount);
             }
         }
-        
+
         /// <summary>
         /// Returns a hash code for this instance.
         /// </summary>
@@ -1012,7 +1018,7 @@ namespace MathNet.Numerics.LinearAlgebra.Complex
                 resultSparseMatrix.NonZerosCount = NonZerosCount + lowerSparseMatrix.NonZerosCount;
                 resultSparseMatrix._nonZeroValues = new Complex[resultSparseMatrix.NonZerosCount];
                 resultSparseMatrix._columnIndices = new int[resultSparseMatrix.NonZerosCount];
-                
+
                 Array.Copy(_nonZeroValues, 0, resultSparseMatrix._nonZeroValues, 0, NonZerosCount);
                 Array.Copy(lowerSparseMatrix._nonZeroValues, 0, resultSparseMatrix._nonZeroValues, NonZerosCount, lowerSparseMatrix.NonZerosCount);
 
@@ -1371,8 +1377,8 @@ namespace MathNet.Numerics.LinearAlgebra.Complex
         /// <param name="result">The result of the negation.</param>
         protected override void DoNegate(Matrix<Complex> result)
         {
-           CopyTo(result);
-           DoMultiply(-1, result);
+            CopyTo(result);
+            DoMultiply(-1, result);
         }
 
         /// <summary>
@@ -1470,5 +1476,39 @@ namespace MathNet.Numerics.LinearAlgebra.Complex
                 }
             }
         }
+
+        /// <summary>
+        /// Iterates throw each element in the matrix (row-wise).
+        /// </summary>
+        /// <returns>The value at the current iteration along with its position (row, column, value).</returns>
+        public override IEnumerable<Tuple<int, int, Complex>> IndexedEnumerator()
+        {
+            for (var row = 0; row < RowCount - 1; row++)
+            {
+                var start = _rowIndex[row];
+                var end = _rowIndex[row + 1];
+
+                if (start == end)
+                {
+                    continue;
+                }
+
+                for (var index = start; index < end; index++)
+                {
+                    yield return new Tuple<int, int, Complex>(row, _columnIndices[index], _nonZeroValues[index]);
+                }
+            }
+
+            var lastRow = _rowIndex.Length - 1;
+
+            if (_rowIndex[lastRow] < NonZerosCount)
+            {
+                for (var index = _rowIndex[lastRow]; index < NonZerosCount; index++)
+                {
+                    yield return new Tuple<int, int, Complex>(lastRow, _columnIndices[index], _nonZeroValues[index]);
+                }
+            }
+        }
     }
 }
+

src/Numerics/LinearAlgebra/Complex32/SparseMatrix.cs

@@ -31,6 +31,7 @@
 namespace MathNet.Numerics.LinearAlgebra.Complex32
 {
     using System;
+    using System.Collections.Generic;
     using Generic;
     using Numerics;
     using Properties;
@@ -1470,5 +1471,38 @@ namespace MathNet.Numerics.LinearAlgebra.Complex32
                 }
             }
         }
+
+        /// <summary>
+        /// Iterates throw each element in the matrix (row-wise).
+        /// </summary>
+        /// <returns>The value at the current iteration along with its position (row, column, value).</returns>
+        public override IEnumerable<Tuple<int, int, Complex32>> IndexedEnumerator()
+        {
+            for (var row = 0; row < RowCount - 1; row++)
+            {
+                var start = _rowIndex[row];
+                var end = _rowIndex[row + 1];
+
+                if (start == end)
+                {
+                    continue;
+                }
+
+                for (var index = start; index < end; index++)
+                {
+                    yield return new Tuple<int, int, Complex32>(row, _columnIndices[index], _nonZeroValues[index]);
+                }
+            }
+
+            var lastRow = _rowIndex.Length - 1;
+
+            if (_rowIndex[lastRow] < NonZerosCount)
+            {
+                for (var index = _rowIndex[lastRow]; index < NonZerosCount; index++)
+                {
+                    yield return new Tuple<int, int, Complex32>(lastRow, _columnIndices[index], _nonZeroValues[index]);
+                }
+            }
+        }
     }
 }

src/Numerics/LinearAlgebra/Double/SparseMatrix.cs

@@ -31,6 +31,7 @@
 namespace MathNet.Numerics.LinearAlgebra.Double
 {
     using System;
+    using System.Collections.Generic;
     using Generic;
     using Properties;
     using Threading;
@@ -1469,5 +1470,38 @@ namespace MathNet.Numerics.LinearAlgebra.Double
                 }
             }
         }
+        
+        /// <summary>
+        /// Iterates throw each element in the matrix (row-wise).
+        /// </summary>
+        /// <returns>The value at the current iteration along with its position (row, column, value).</returns>
+        public override IEnumerable<Tuple<int, int, double>> IndexedEnumerator()
+        {
+            for (var row = 0; row < RowCount - 1; row++)
+            {
+                var start = _rowIndex[row];
+                var end = _rowIndex[row + 1];
+                
+                if (start == end)
+                {
+                    continue;
+                }
+
+                for (var index = start; index < end; index++)
+                {
+                    yield return new Tuple<int, int, double>(row, _columnIndices[index], _nonZeroValues[index]);
+                }
+            }
+
+            var lastRow = _rowIndex.Length - 1;
+
+            if (_rowIndex[lastRow] < NonZerosCount)
+            {
+                for (var index = _rowIndex[lastRow]; index < NonZerosCount; index++)
+                {
+                    yield return new Tuple<int, int, double>(lastRow, _columnIndices[index], _nonZeroValues[index]);
+                }
+            }
+        }
     }
 }

src/Numerics/LinearAlgebra/Generic/Matrix.cs

@@ -1788,5 +1788,20 @@ namespace MathNet.Numerics.LinearAlgebra.Generic
         /// <summary>Calculates the infinity norm of this matrix.</summary>
         /// <returns>The infinity norm of this matrix.</returns>   
         public abstract T InfinityNorm();
+
+        /// <summary>
+        /// Iterates throw each element in the matrix (row-wise).
+        /// </summary>
+        /// <returns>The value at the current iteration along with its position (row, column, value).</returns>
+        public virtual IEnumerable<Tuple<int, int, T>> IndexedEnumerator()
+        {
+            for (var row = 0; row < RowCount; row++)
+            {
+                for (var column = 0; column < ColumnCount; column++)
+                {
+                    yield return new Tuple<int, int, T>(row, column, At(row, column));
+                }
+            }
+        }
     }
 }

src/Numerics/LinearAlgebra/Single/SparseMatrix.cs

@@ -31,6 +31,7 @@
 namespace MathNet.Numerics.LinearAlgebra.Single
 {
     using System;
+    using System.Collections.Generic;
     using Generic;
     using Properties;
     using Threading;
@@ -1469,5 +1470,38 @@ namespace MathNet.Numerics.LinearAlgebra.Single
                 }
             }
         }
+
+        /// <summary>
+        /// Iterates throw each element in the matrix (row-wise).
+        /// </summary>
+        /// <returns>The value at the current iteration along with its position (row, column, value).</returns>
+        public override IEnumerable<Tuple<int, int, float>> IndexedEnumerator()
+        {
+            for (var row = 0; row < RowCount - 1; row++)
+            {
+                var start = _rowIndex[row];
+                var end = _rowIndex[row + 1];
+
+                if (start == end)
+                {
+                    continue;
+                }
+
+                for (var index = start; index < end; index++)
+                {
+                    yield return new Tuple<int, int, float>(row, _columnIndices[index], _nonZeroValues[index]);
+                }
+            }
+
+            var lastRow = _rowIndex.Length - 1;
+
+            if (_rowIndex[lastRow] < NonZerosCount)
+            {
+                for (var index = _rowIndex[lastRow]; index < NonZerosCount; index++)
+                {
+                    yield return new Tuple<int, int, float>(lastRow, _columnIndices[index], _nonZeroValues[index]);
+                }
+            }
+        }
     }
 }