From d7124278af509ece62b719e29da4cdf66af8adb1 Mon Sep 17 00:00:00 2001
From: Christoph Ruegg <git@cdrnet.ch>
Date: Thu, 29 May 2014 13:42:20 +0200
Subject: [PATCH] LA: fix IsConjugateSymmetric to ensure diagonal is real

---
 src/Numerics/LinearAlgebra/Complex/DenseMatrix.cs   | 13 +++++++++++--
 .../LinearAlgebra/Complex/DiagonalMatrix.cs         |  8 ++++++++
 src/Numerics/LinearAlgebra/Complex/Matrix.cs        |  8 ++++++++
 src/Numerics/LinearAlgebra/Complex32/DenseMatrix.cs |  9 +++++++++
 .../LinearAlgebra/Complex32/DiagonalMatrix.cs       |  8 ++++++++
 src/Numerics/LinearAlgebra/Complex32/Matrix.cs      |  8 ++++++++
 6 files changed, 52 insertions(+), 2 deletions(-)

diff --git a/src/Numerics/LinearAlgebra/Complex/DenseMatrix.cs b/src/Numerics/LinearAlgebra/Complex/DenseMatrix.cs
index b8e7afc5..f1cd2171 100644
--- a/src/Numerics/LinearAlgebra/Complex/DenseMatrix.cs
+++ b/src/Numerics/LinearAlgebra/Complex/DenseMatrix.cs
@@ -669,7 +669,7 @@ namespace MathNet.Numerics.LinearAlgebra.Complex
                 }
                 return;
             }
-            
+
             base.DoMultiply(other, result);
         }
 
@@ -804,7 +804,7 @@ namespace MathNet.Numerics.LinearAlgebra.Complex
                     denseResult.Values);
                 return;
             }
-            
+
             base.DoTransposeThisAndMultiply(rightSide, result);
         }
 
@@ -1263,6 +1263,15 @@ namespace MathNet.Numerics.LinearAlgebra.Complex
                 return false;
             }
 
+            int stride = RowCount + 1;
+            for (var k = 0; k < _values.Length; k += stride)
+            {
+                if (!_values[k].IsReal())
+                {
+                    return false;
+                }
+            }
+
             for (var j = 0; j < ColumnCount; j++)
             {
                 var index = j * RowCount;
diff --git a/src/Numerics/LinearAlgebra/Complex/DiagonalMatrix.cs b/src/Numerics/LinearAlgebra/Complex/DiagonalMatrix.cs
index 8e1a6e0a..04fb7f65 100644
--- a/src/Numerics/LinearAlgebra/Complex/DiagonalMatrix.cs
+++ b/src/Numerics/LinearAlgebra/Complex/DiagonalMatrix.cs
@@ -1018,6 +1018,14 @@ namespace MathNet.Numerics.LinearAlgebra.Complex
         /// </summary>
         public override sealed bool IsConjugateSymmetric()
         {
+            for (var k = 0; k < _data.Length; k ++)
+            {
+                if (!_data[k].IsReal())
+                {
+                    return false;
+                }
+            }
+
             return true;
         }
     }
diff --git a/src/Numerics/LinearAlgebra/Complex/Matrix.cs b/src/Numerics/LinearAlgebra/Complex/Matrix.cs
index 83695eb4..2c508211 100644
--- a/src/Numerics/LinearAlgebra/Complex/Matrix.cs
+++ b/src/Numerics/LinearAlgebra/Complex/Matrix.cs
@@ -671,6 +671,14 @@ namespace MathNet.Numerics.LinearAlgebra.Complex
                 return false;
             }
 
+            for (var k = 0; k < RowCount; k++)
+            {
+                if (!At(k, k).IsReal())
+                {
+                    return false;
+                }
+            }
+
             for (var row = 0; row < RowCount; row++)
             {
                 for (var column = row + 1; column < ColumnCount; column++)
diff --git a/src/Numerics/LinearAlgebra/Complex32/DenseMatrix.cs b/src/Numerics/LinearAlgebra/Complex32/DenseMatrix.cs
index a756020e..fd6a295f 100644
--- a/src/Numerics/LinearAlgebra/Complex32/DenseMatrix.cs
+++ b/src/Numerics/LinearAlgebra/Complex32/DenseMatrix.cs
@@ -1260,6 +1260,15 @@ namespace MathNet.Numerics.LinearAlgebra.Complex32
                 return false;
             }
 
+            int stride = RowCount + 1;
+            for (var k = 0; k < _values.Length; k += stride)
+            {
+                if (!_values[k].IsReal())
+                {
+                    return false;
+                }
+            }
+
             for (var j = 0; j < ColumnCount; j++)
             {
                 var index = j * RowCount;
diff --git a/src/Numerics/LinearAlgebra/Complex32/DiagonalMatrix.cs b/src/Numerics/LinearAlgebra/Complex32/DiagonalMatrix.cs
index 55f422cd..7a25a5d6 100644
--- a/src/Numerics/LinearAlgebra/Complex32/DiagonalMatrix.cs
+++ b/src/Numerics/LinearAlgebra/Complex32/DiagonalMatrix.cs
@@ -1012,6 +1012,14 @@ namespace MathNet.Numerics.LinearAlgebra.Complex32
         /// </summary>
         public override sealed bool IsConjugateSymmetric()
         {
+            for (var k = 0; k < _data.Length; k++)
+            {
+                if (!_data[k].IsReal())
+                {
+                    return false;
+                }
+            }
+
             return true;
         }
     }
diff --git a/src/Numerics/LinearAlgebra/Complex32/Matrix.cs b/src/Numerics/LinearAlgebra/Complex32/Matrix.cs
index e8dded99..79451d43 100644
--- a/src/Numerics/LinearAlgebra/Complex32/Matrix.cs
+++ b/src/Numerics/LinearAlgebra/Complex32/Matrix.cs
@@ -665,6 +665,14 @@ namespace MathNet.Numerics.LinearAlgebra.Complex32
                 return false;
             }
 
+            for (var k = 0; k < RowCount; k++)
+            {
+                if (!At(k, k).IsReal())
+                {
+                    return false;
+                }
+            }
+
             for (var row = 0; row < RowCount; row++)
             {
                 for (var column = row + 1; column < ColumnCount; column++)