LA: more efficient matrix InsertRow/InsertColumn #207

src/Numerics/LinearAlgebra/Matrix.cs

@@ -649,19 +649,9 @@ namespace MathNet.Numerics.LinearAlgebra
             }
 
             var result = Build.SameAs(this, RowCount, ColumnCount + 1);
-
-            for (var i = 0; i < columnIndex; i++)
-            {
-                result.SetColumn(i, Column(i));
-            }
-
+            Storage.CopySubMatrixTo(result.Storage, 0, 0, RowCount, 0, 0, columnIndex, skipClearing: true);
             result.SetColumn(columnIndex, column);
-
-            for (var i = columnIndex + 1; i < ColumnCount + 1; i++)
-            {
-                result.SetColumn(i, Column(i - 1));
-            }
-
+            Storage.CopySubMatrixTo(result.Storage, 0, 0, RowCount, columnIndex, columnIndex + 1, ColumnCount - columnIndex, skipClearing: true);
             return result;
         }
 
@@ -756,19 +746,9 @@ namespace MathNet.Numerics.LinearAlgebra
             }
 
             var result = Build.SameAs(this, RowCount + 1, ColumnCount);
-
-            for (var i = 0; i < rowIndex; i++)
-            {
-                result.SetRow(i, Row(i));
-            }
-
+            Storage.CopySubMatrixTo(result.Storage, 0, 0, rowIndex, 0, 0, ColumnCount, skipClearing: true);
             result.SetRow(rowIndex, row);
-
-            for (var i = rowIndex + 1; i < RowCount + 1; i++)
-            {
-                result.SetRow(i, Row(i - 1));
-            }
-
+            Storage.CopySubMatrixTo(result.Storage, rowIndex, rowIndex+1, RowCount - rowIndex, 0, 0, ColumnCount, skipClearing: true);
             return result;
         }
 

src/Numerics/LinearAlgebra/Storage/MatrixStorage.cs

@@ -270,6 +270,11 @@ namespace MathNet.Numerics.LinearAlgebra.Storage
                 throw new ArgumentNullException("target");
             }
 
+            if (rowCount == 0 || columnCount == 0)
+            {
+                return;
+            }
+
             if (ReferenceEquals(this, target))
             {
                 throw new NotSupportedException();
@@ -319,6 +324,11 @@ namespace MathNet.Numerics.LinearAlgebra.Storage
                 throw new ArgumentNullException("target");
             }
 
+            if (columnCount == 0)
+            {
+                return;
+            }
+
             ValidateSubRowRange(target, rowIndex, sourceColumnIndex, targetColumnIndex, columnCount);
             CopySubRowToUnchecked(target, rowIndex, sourceColumnIndex, targetColumnIndex, columnCount, skipClearing);
         }
@@ -355,6 +365,11 @@ namespace MathNet.Numerics.LinearAlgebra.Storage
                 throw new ArgumentNullException("target");
             }
 
+            if (rowCount == 0)
+            {
+                return;
+            }
+
             ValidateSubColumnRange(target, columnIndex, sourceRowIndex, targetRowIndex, rowCount);
             CopySubColumnToUnchecked(target, columnIndex, sourceRowIndex, targetRowIndex, rowCount, skipClearing);
         }

src/UnitTests/LinearAlgebraTests/MatrixStructureTheory.Access.cs

@@ -656,14 +656,14 @@ namespace MathNet.Numerics.UnitTests.LinearAlgebraTests
             Assert.That(() => m.SetSubMatrix(0, 1, 0, 1, default(Matrix<T>)), Throws.InstanceOf<NullReferenceException>());
             Assert.That(() => m.SetSubMatrix(-1, 1, 0, 1, Matrix<T>.Build.Dense(1, 1)), Throws.InstanceOf<ArgumentOutOfRangeException>());
             Assert.That(() => m.SetSubMatrix(matrix.RowCount, 1, 0, 1, Matrix<T>.Build.Dense(1, 1)), Throws.InstanceOf<ArgumentOutOfRangeException>());
-            Assert.That(() => m.SetSubMatrix(0, 0, 0, 1, Matrix<T>.Build.Dense(1, 1)), Throws.InstanceOf<ArgumentOutOfRangeException>());
             Assert.That(() => m.SetSubMatrix(0, 1, -1, 1, Matrix<T>.Build.Dense(1, 1)), Throws.InstanceOf<ArgumentOutOfRangeException>());
             Assert.That(() => m.SetSubMatrix(0, 1, matrix.ColumnCount, 1, Matrix<T>.Build.Dense(1, 1)), Throws.InstanceOf<ArgumentOutOfRangeException>());
-            Assert.That(() => m.SetSubMatrix(0, 1, 0, 0, Matrix<T>.Build.Dense(1, 1)), Throws.InstanceOf<ArgumentOutOfRangeException>());
             
             // Usually invalid, but not for SetSubMatrix (since size is explicitly provided)
             Assert.That(() => m.SetSubMatrix(0, 1, 0, 1, Matrix<T>.Build.Dense(1, 2)), Throws.Nothing);
             Assert.That(() => m.SetSubMatrix(0, 1, 0, 1, Matrix<T>.Build.Dense(2, 1)), Throws.Nothing);
+            Assert.That(() => m.SetSubMatrix(0, 0, 0, 1, Matrix<T>.Build.Dense(1, 1)), Throws.Nothing);
+            Assert.That(() => m.SetSubMatrix(0, 1, 0, 0, Matrix<T>.Build.Dense(1, 1)), Throws.Nothing);
         }
     }
 }