tphase algo done

twoPhaseSimplex.cs

@@ -41,12 +41,42 @@ class twoPhaseSimplex
         table = prepareTable(newTable, constraintsList);
 
         // print table
-        printTable(table, varCount);
+        printTablePhaseOne(table, varCount);
+
+        flipZ(table);
+        printTablePhaseOne(table, varCount);
+        bool isOptimal = isOptimalPhaseOne(table);
+        while (!isOptimal)
+        {
+            int pivotCol = findPivotCol(table);
+            List<float> ratio = ratioTest(table, pivotCol);
+            int pivotRow = findPivotRow(ratio);
+            table = pivotTable(table, pivotRow, pivotCol);
+            printTablePhaseOne(table, varCount);
+            isOptimal = isOptimalPhaseOne(table);
+        }
+
+        table = dropCol(table, varCount);
+        isOptimal = isOptimalPhaseTwo(table);
+        printTablePhaseTwo(table, varCount);
+        while (!isOptimal)
+        {
+            int pivotCol = findPivotCol(table);
+            List<float> ratio = ratioTest(table, pivotCol);
+            int pivotRow = findPivotRow(ratio);
+            table = pivotTable(table, pivotRow, pivotCol);
+            printTablePhaseTwo(table, varCount);
+            isOptimal = isOptimalPhaseTwo(table);
+        }
+        
+
+
 
     }
 
-    void printTable(List<List<float>> table, int varCount)
+    void printTablePhaseOne(List<List<float>> table, int varCount)
     {
+        int count = 1;
         string[] headers = new string[table[0].Count];
         for (int i = 0; i < table[0].Count; i++)
         {
@@ -56,10 +86,48 @@ class twoPhaseSimplex
             }
             else if (i < table[0].Count - 1)
             {
-                headers[i] = "e" + (i - varCount + 1);
-                headers[i+1] = "a" + (i - varCount + 1);
-                headers[i+2] = "s" + (i - varCount + 1);
+                headers[i] = "e" + (count);
+                headers[i+1] = "a" + (count);
+                headers[i+2] = "s" + (count);
                 i = i + 2;
+                count++;
+            }
+            else
+            {
+                headers[i] = "rhs";
+            }
+        }
+        var conTable = new ConsoleTable(headers);
+        foreach (List<float> row in table)
+        {
+            // convert row to object array
+            object[] rowArray = new object[row.Count];
+            for (int i = 0; i < row.Count; i++)
+            {
+                rowArray[i] = row[i];
+            }
+            conTable.AddRow(rowArray);
+        }
+        conTable.Write(Format.Alternative);
+        
+    }
+
+    void printTablePhaseTwo(List<List<float>> table, int varCount)
+    {
+        int count = 1;
+        string[] headers = new string[table[0].Count];
+        for (int i = 0; i < table[0].Count; i++)
+        {
+            if (i < varCount)
+            {
+                headers[i] = "x" + (i + 1);
+            }
+            else if (i < table[0].Count - 1)
+            {
+                headers[i] = "e" + (count);
+                headers[i+1] = "s" + (count);
+                i = i + 1;
+                count++;
             }
             else
             {
@@ -94,21 +162,32 @@ class twoPhaseSimplex
             }
             newTable.Add(newRow);
         }
+        List<int> rowsWithW = new List<int>();
         List<string> signs = new List<string>();
         foreach (Constraints constraint in constraints)
         {
             signs.Add(constraint.sign);    
         }
+        // ammount of values in newTable startring from newTable[1])
+        int varCount = 0;
+        for (int i = 1; i < newTable.Count; i++)
+        {
+            varCount = varCount + newTable[i].Count;
+        }
         for (int i = 0; i < signs.Count ; i++)
         {
             table[0].Add(0);
             table[0].Add(0);
             table[0].Add(0);
+            int temp = (newTable[i+1].Count-1) * signs.Count;
+
+            
             // add 3 0s to each row for every column in table
-            for (int j = 0; j < newTable[i+1].Count-1; j++)
+            for (int j = 0; j < signs.Count ; j++)
             {
                 if (signs[i] == ">=")
                 {
+                    // make s = 1 
                     if (i == j)
                     {
                         table[i+1].Add(0);
@@ -124,11 +203,13 @@ class twoPhaseSimplex
                 }
                 else if (signs[i] == "<=")
                 {
+                    //make e and a = 1
                     if (i == j)
                     {
-                        table[i+1].Add(1);
+                        table[i+1].Add(-1);
                         table[i+1].Add(1);
                         table[i+1].Add(0);
+                        rowsWithW.Add(i+1);
                     }
                     else
                     {
@@ -139,11 +220,13 @@ class twoPhaseSimplex
                 }
                 else if (signs[i] == "=")
                 {
+                    // make a = 1
                     if (i == j)
                     {
                         table[i+1].Add(0);
                         table[i+1].Add(1);
                         table[i+1].Add(0);
+                        rowsWithW.Add(i+1);
                     }
                     else
                     {
@@ -155,14 +238,198 @@ class twoPhaseSimplex
             }
         }
         table[0].Add(0);
+        // create list of floats called wRow size table[0].Count - 1
+        List<float> wRow = new List<float>();
+        for (int i = 0; i < table[0].Count; i++)
+        {
+            wRow.Add(0);
+        }
+        for (int i = 0; i < table[0].Count; i++)
+        {
+            // if i is in rowsWithW
+            if (rowsWithW.Contains(i))
+            {
+                for (int j = 0; j < wRow.Count; j++)
+                {
+                    wRow[j] = wRow[j] + (-table[i][j]);
+                }
+            }
+        }
+        //add wRow to the start of table
+        table.Insert(1, wRow);
+        
         // remove intex newTable.Count-1 from table and place it in the back of table
-        for (int i = 1; i < table.Count; i++)
+        for (int i = 2; i < table.Count; i++)
         {
             table[i].RemoveAt(newTable.Count-1);
-            table[i].Add(newTable[i][newTable.Count-1]);
+            table[i].Add(newTable[i-1][newTable[i-1].Count-1]);
 
         }
+        // remove the value of newTable.Count-1 from table[1] and place it in the back of table[1]
+        float lastValue = table[1][newTable.Count-1];
+        table[1].RemoveAt(newTable.Count-1);
+        table[1].Add(lastValue);
+        
+        
         
         return table;
     }
+        static List<List<float>> flipZ(List<List<float>> table)
+    {
+        for (int i = 0; i < table[0].Count; i++)
+        {
+            if (table[0][i] > 0)
+            {
+                table[0][i] = -table[0][i];
+            }
+        }
+        return table;
+    }
+
+        static int findPivotCol(List<List<float>> table)
+    {
+        float largest = 0;
+        int largestIndex = 0;
+        for (int i = 0; i < table[0].Count; i++)
+        {
+            if (table[0][i] < largest)
+            {
+                largest = table[0][i];
+                largestIndex = i;
+            }
+        }
+        return largestIndex;
+    }
+
+        static List<float> ratioTest(List<List<float>> table, int testCol)
+    {
+        List<float> ratios = new List<float>();
+        for (int i = 1; i < table.Count; i++)
+        {
+            if (table[i][testCol] != 0)
+            {
+                ratios.Add(table[i][table[i].Count - 1] / table[i][testCol]);
+            }
+            else
+            {
+                ratios.Add(float.MaxValue);
+            }
+        }
+        return ratios;
+    }
+        static int findPivotRow(List<float> ratios)
+    {
+        float smallest = float.MaxValue;
+        int smallestIndex = 0;
+        for (int i = 0; i < ratios.Count; i++)
+        {
+            if (ratios[i] < smallest && ratios[i] > 0.0)
+            {
+                smallest = ratios[i];
+                smallestIndex = i;
+            }
+        }
+        return smallestIndex;
+    }
+
+        static List<List<float>> pivotTable(List<List<float>> table, int pivotRow, int pivotCol)
+    {
+        //clone table in to newTable
+        List<List<float>> newTable = new List<List<float>>();
+        foreach (List<float> row in table)
+        {
+            List<float> newRow = new List<float>();
+            for (int i = 0; i < row.Count; i++)
+            {
+                newRow.Add(row[i]);
+            }
+            newTable.Add(newRow);
+        }
+        var pivotPoint = newTable[pivotRow + 1][pivotCol];
+        // divide pivot row by pivot point
+        for (int i = 0; i < newTable[pivotRow + 1].Count; i++)
+        {
+            newTable[pivotRow + 1][i] = newTable[pivotRow + 1][i] / pivotPoint;
+        }
+        // current possition-(pivot_row*new_table pivot_point)
+        for (int i = 0; i < newTable.Count; i++)
+        {
+            if (i != pivotRow + 1)
+            {
+                var currentPossition = newTable[i][pivotCol];
+                for (int j = 0; j < newTable[i].Count; j++)
+                {
+                    newTable[i][j] = newTable[i][j] - (currentPossition * newTable[pivotRow + 1][j]);
+                }
+            }
+        }
+        return newTable;
+    }
+
+    //check if the table is optimal first phase
+    // table is optimal if all values in table[1] are positive
+
+
+    static bool isOptimalPhaseOne(List<List<float>> table)
+    {
+        int wIndex = 0;
+        for (int i = 0; i < table[1].Count; i++)
+        {
+            if (table[1][i] < 0)
+            {
+                wIndex = i;
+            }
+        }
+        if (wIndex == 0)
+        {
+            return true;
+        }
+        else
+        {
+            return false;
+        }
+    }
+
+
+    static bool isOptimalPhaseTwo(List<List<float>> table)
+    {
+        int wIndex = 0;
+        for (int i = 0; i < table[0].Count; i++)
+        {
+            if (table[0][i] < 0)
+            {
+                wIndex = i;
+            }
+        }
+        if (wIndex == 0)
+        {
+            return true;
+        }
+        else
+        {
+            return false;
+        }
+    }
+
+
+    //drop all a coloumn from the table and drop w row from the table
+    static List<List<float>> dropCol(List<List<float>> table, int varCount)
+    {
+        table.RemoveAt(1);
+        
+
+        // for each row in table drop the varCount-1th element
+        for (int i = 0; i < table.Count; i++)
+        {
+            for (int j = varCount + 1; j < table[i].Count - 1; j+=3)
+            {
+                table[i].RemoveAt(j);
+                j = j - 1;
+            }
+        }
+        return table;
+
+    }
+
+    
 }