M2

src/Algebra/Matrices/NormalMatrices/FDiagonalMatrix.cs

@@ -0,0 +1,79 @@
+using Skeleton.Algebra.FixableObjects;
+using Skeleton.Algebra.ScalarFieldStructure;
+
+namespace Skeleton.Algebra;
+
+public partial class CategoryOf<TDimension>
+{
+    public static partial class OnField<TScalar>
+    {
+        /// <inheritdoc />
+        public class FDiagonalMatrix : FNormalMatrix
+        {
+            /// <inheritdoc />
+            public FDiagonalMatrix()
+            {
+                U = One;
+                D = AsMatrix;
+            }
+
+            /// <inheritdoc />
+            public FDiagonalMatrix(IEnumerable<FVector> es, bool row = true) : base(es, row) =>
+                this.PostConstructionFix();
+            
+            /// <inheritdoc />
+            public FDiagonalMatrix(params TScalar[] es)
+            {
+                U = One;
+                if (es.Length == FDim)
+                    for (int i = 1; i <= FDim; i++)
+                        this[i, i] = es[i - 1];
+                else
+                    for (int i = 1; i <= FDim; i++)
+                    for (int j = 1; j <= FDim; j++)
+                        this[i, j] = es[i - 1 + (j - 1) * FDim];
+                this.PostConstructionFix();
+            }
+            internal override bool NeedFix => base.NeedFix || !Property.IsDiagonal;
+            internal override void Fix()
+            {
+                for (int i = 1; i <= Dim; i++)
+                {
+                    for (int j = i + 1; j <= Dim; j++)
+                    {
+                        this[i, j] = StaticAccess<TScalar>.AdditionUnit;
+                        this[j, i] = StaticAccess<TScalar>.AdditionUnit;
+                    }
+                }
+                base.Fix();
+            }
+
+            /// <summary>
+            /// log of the normal matrix
+            /// </summary>
+            /// <returns></returns>
+            public FDiagonalMatrix Log()
+            {
+                FDiagonalMatrix res = new();
+                for (int i = 1; i <= Dim; i++)
+                    res[i, i] = FieldStructure.Log(this[i, i]);
+                return res;
+            }
+
+            /// <summary>
+            /// exp of the normal matrix
+            /// </summary>
+            /// <returns></returns>
+            public FDiagonalMatrix Exp()
+            {
+                FDiagonalMatrix res = new();
+                for (int i = 1; i <= Dim; i++)
+                    res[i, i] = FieldStructure.Exp(this[i, i]);
+                return res;
+            }
+
+            internal override void UnitaryFix(FMatrix a) { }
+
+        }
+    }
+}