LA: Matrix Column/Row sums and absolute-sums

src/Numerics/LinearAlgebra/Complex/Matrix.cs

@@ -204,6 +204,46 @@ namespace MathNet.Numerics.LinearAlgebra.Complex
             return result;
         }
 
+        /// <summary>
+        /// Calculates the value sum of each row vector.
+        /// </summary>
+        public override Vector<Complex> RowSums()
+        {
+            var ret = new Complex[RowCount];
+            Storage.FoldByRowUnchecked(ret, (s, x) => s + x, (x, c) => x, ret, Zeros.AllowSkip);
+            return Vector<Complex>.Build.Dense(ret);
+        }
+
+        /// <summary>
+        /// Calculates the absolute value sum of each row vector.
+        /// </summary>
+        public override Vector<Complex> RowAbsoluteSums()
+        {
+            var ret = new Complex[RowCount];
+            Storage.FoldByRowUnchecked(ret, (s, x) => s + x.Magnitude, (x, c) => x, ret, Zeros.AllowSkip);
+            return Vector<Complex>.Build.Dense(ret);
+        }
+
+        /// <summary>
+        /// Calculates the value sum of each column vector.
+        /// </summary>
+        public override Vector<Complex> ColumnSums()
+        {
+            var ret = new Complex[ColumnCount];
+            Storage.FoldByColumnUnchecked(ret, (s, x) => s + x, (x, c) => x, ret, Zeros.AllowSkip);
+            return Vector<Complex>.Build.Dense(ret);
+        }
+
+        /// <summary>
+        /// Calculates the absolute value sum of each column vector.
+        /// </summary>
+        public override Vector<Complex> ColumnAbsoluteSums()
+        {
+            var ret = new Complex[ColumnCount];
+            Storage.FoldByColumnUnchecked(ret, (s, x) => s + x.Magnitude, (x, c) => x, ret, Zeros.AllowSkip);
+            return Vector<Complex>.Build.Dense(ret);
+        }
+
         /// <summary>
         /// Returns the conjugate transpose of this matrix.
         /// </summary>

src/Numerics/LinearAlgebra/Complex32/Matrix.cs

@@ -198,6 +198,46 @@ namespace MathNet.Numerics.LinearAlgebra.Complex32
             return result;
         }
 
+        /// <summary>
+        /// Calculates the value sum of each row vector.
+        /// </summary>
+        public override Vector<Complex32> RowSums()
+        {
+            var ret = new Complex32[RowCount];
+            Storage.FoldByRowUnchecked(ret, (s, x) => s + x, (x, c) => x, ret, Zeros.AllowSkip);
+            return Vector<Complex32>.Build.Dense(ret);
+        }
+
+        /// <summary>
+        /// Calculates the absolute value sum of each row vector.
+        /// </summary>
+        public override Vector<Complex32> RowAbsoluteSums()
+        {
+            var ret = new Complex32[RowCount];
+            Storage.FoldByRowUnchecked(ret, (s, x) => s + x.Magnitude, (x, c) => x, ret, Zeros.AllowSkip);
+            return Vector<Complex32>.Build.Dense(ret);
+        }
+
+        /// <summary>
+        /// Calculates the value sum of each column vector.
+        /// </summary>
+        public override Vector<Complex32> ColumnSums()
+        {
+            var ret = new Complex32[ColumnCount];
+            Storage.FoldByColumnUnchecked(ret, (s, x) => s + x, (x, c) => x, ret, Zeros.AllowSkip);
+            return Vector<Complex32>.Build.Dense(ret);
+        }
+
+        /// <summary>
+        /// Calculates the absolute value sum of each column vector.
+        /// </summary>
+        public override Vector<Complex32> ColumnAbsoluteSums()
+        {
+            var ret = new Complex32[ColumnCount];
+            Storage.FoldByColumnUnchecked(ret, (s, x) => s + x.Magnitude, (x, c) => x, ret, Zeros.AllowSkip);
+            return Vector<Complex32>.Build.Dense(ret);
+        }
+
         /// <summary>
         /// Returns the conjugate transpose of this matrix.
         /// </summary>

src/Numerics/LinearAlgebra/Double/Matrix.cs

@@ -196,6 +196,46 @@ namespace MathNet.Numerics.LinearAlgebra.Double
             return result;
         }
 
+        /// <summary>
+        /// Calculates the value sum of each row vector.
+        /// </summary>
+        public override Vector<double> RowSums()
+        {
+            var ret = new double[RowCount];
+            Storage.FoldByRowUnchecked(ret, (s, x) => s + x, (x, c) => x, ret, Zeros.AllowSkip);
+            return Vector<double>.Build.Dense(ret);
+        }
+
+        /// <summary>
+        /// Calculates the absolute value sum of each row vector.
+        /// </summary>
+        public override Vector<double> RowAbsoluteSums()
+        {
+            var ret = new double[RowCount];
+            Storage.FoldByRowUnchecked(ret, (s, x) => s + Math.Abs(x), (x, c) => x, ret, Zeros.AllowSkip);
+            return Vector<double>.Build.Dense(ret);
+        }
+
+        /// <summary>
+        /// Calculates the value sum of each column vector.
+        /// </summary>
+        public override Vector<double> ColumnSums()
+        {
+            var ret = new double[ColumnCount];
+            Storage.FoldByColumnUnchecked(ret, (s, x) => s + x, (x, c) => x, ret, Zeros.AllowSkip);
+            return Vector<double>.Build.Dense(ret);
+        }
+
+        /// <summary>
+        /// Calculates the absolute value sum of each column vector.
+        /// </summary>
+        public override Vector<double> ColumnAbsoluteSums()
+        {
+            var ret = new double[ColumnCount];
+            Storage.FoldByColumnUnchecked(ret, (s, x) => s + Math.Abs(x), (x, c) => x, ret, Zeros.AllowSkip);
+            return Vector<double>.Build.Dense(ret);
+        }
+
         /// <summary>
         /// Returns the conjugate transpose of this matrix.
         /// </summary>

src/Numerics/LinearAlgebra/Matrix.Arithmetic.cs

@@ -1674,6 +1674,26 @@ namespace MathNet.Numerics.LinearAlgebra
         /// </summary>
         public abstract Matrix<T> NormalizeColumns(double norm);
 
+        /// <summary>
+        /// Calculates the value sum of each row vector.
+        /// </summary>
+        public abstract Vector<T> RowSums();
+
+        /// <summary>
+        /// Calculates the value sum of each column vector.
+        /// </summary>
+        public abstract Vector<T> ColumnSums();
+
+        /// <summary>
+        /// Calculates the absolute value sum of each row vector.
+        /// </summary>
+        public abstract Vector<T> RowAbsoluteSums();
+
+        /// <summary>
+        /// Calculates the absolute value sum of each column vector.
+        /// </summary>
+        public abstract Vector<T> ColumnAbsoluteSums();
+
         #region Exceptions - possibly move elsewhere?
 
         internal static Exception DimensionsDontMatch<TException>(Matrix<T> left, Matrix<T> right, Matrix<T> result, string paramName = null)

src/Numerics/LinearAlgebra/Single/Matrix.cs

@@ -195,6 +195,45 @@ namespace MathNet.Numerics.LinearAlgebra.Single
             Storage.MapIndexedTo(result.Storage, (i, j, x) => (float)norminv[j]*x, Zeros.AllowSkip, ExistingData.AssumeZeros);
             return result;
         }
+        /// <summary>
+        /// Calculates the value sum of each row vector.
+        /// </summary>
+        public override Vector<float> RowSums()
+        {
+            var ret = new float[RowCount];
+            Storage.FoldByRowUnchecked(ret, (s, x) => s + x, (x, c) => x, ret, Zeros.AllowSkip);
+            return Vector<float>.Build.Dense(ret);
+        }
+
+        /// <summary>
+        /// Calculates the absolute value sum of each row vector.
+        /// </summary>
+        public override Vector<float> RowAbsoluteSums()
+        {
+            var ret = new float[RowCount];
+            Storage.FoldByRowUnchecked(ret, (s, x) => s + Math.Abs(x), (x, c) => x, ret, Zeros.AllowSkip);
+            return Vector<float>.Build.Dense(ret);
+        }
+
+        /// <summary>
+        /// Calculates the value sum of each column vector.
+        /// </summary>
+        public override Vector<float> ColumnSums()
+        {
+            var ret = new float[ColumnCount];
+            Storage.FoldByColumnUnchecked(ret, (s, x) => s + x, (x, c) => x, ret, Zeros.AllowSkip);
+            return Vector<float>.Build.Dense(ret);
+        }
+
+        /// <summary>
+        /// Calculates the absolute value sum of each column vector.
+        /// </summary>
+        public override Vector<float> ColumnAbsoluteSums()
+        {
+            var ret = new float[ColumnCount];
+            Storage.FoldByColumnUnchecked(ret, (s, x) => s + Math.Abs(x), (x, c) => x, ret, Zeros.AllowSkip);
+            return Vector<float>.Build.Dense(ret);
+        }
 
         /// <summary>
         /// Returns the conjugate transpose of this matrix.