markov

Esiur.Analysis/Graph/Matrix.cs

@@ -0,0 +1,75 @@
+using System;
+using System.Collections.Generic;
+using System.Data.Common;
+using System.Text;
+
+namespace Esiur.Analysis.Graph
+{
+    public class Matrix<T> where T : struct
+    {
+        internal T[,] value;
+
+        public int Rows => value.GetLength(0);
+        public int Columns => value.GetLength(1);
+
+        public T this[int x, int y] => value[x, y];
+
+        public Matrix(T[,] value)
+        {
+            this.value = value;
+        }
+
+        public static Matrix<T> operator *(Matrix<T> a, Matrix<T> b)
+            => Multiply(a, b);
+
+        public  Matrix<T> Pow(int power)
+        {
+            var rt = this;
+            for (var i = 1; i < power; i++)
+                rt = rt * rt;
+            return rt;
+        }
+
+        public override string ToString()
+        {
+            var rt = "";
+            for (var i = 0; i < Rows; i++)
+            {
+                rt += "|";
+
+                for (var j = 0; j < Columns - 1; j++)
+                    rt += value[i, j] + ",";
+
+                rt += value[i, Columns - 1] + "|";
+            }
+
+            return rt;
+        }
+
+        public static Matrix<T> Multiply<T>(Matrix<T> a, Matrix<T> b) where T : struct
+        {
+
+
+            if (a.Columns != b.Rows)
+                throw new ArgumentException("`a` rows do not match `b` columns.");
+
+
+            T[,] rt = new T[a.Rows, b.Columns];
+
+            for (int i = 0; i < a.Rows; i++)
+            { // aRow
+                for (int j = 0; j < b.Columns; j++)
+                { // bColumn
+                    for (int k = 0; k < a.Columns; k++)
+                    { // aColumn
+                        dynamic aValue = a[i, k];
+                        dynamic bValue = b[k, j];
+                        rt[i, j] += aValue * bValue;// a[i, k] * b[k, j];
+                    }
+                }
+            }
+
+            return new Matrix<T>(rt);
+        }
+    }
+}