public static SparseMatrix Read2MatrixToSparseMatrix(List<DTMCState> scc, List<DTMCState> output)
{
int inputSize = scc.Count;
int outputSize = output.Count;
int column = inputSize + outputSize;
var matrix = new SparseMatrix(inputSize,column);
var dtmcState2Number = new Dictionary<DTMCState, int>(column);
//var number2dtmcState = new Dictionary<int, DTMCState>(column);
//assign coordination first
int i = 0;
foreach (DTMCState mdpState in scc)
{
dtmcState2Number.Add(mdpState, i);
i++;
}
foreach (DTMCState mdpState in output)
{
dtmcState2Number.Add(mdpState, i);
i++;
}
//assign rows to matrix
foreach (DTMCState dtmcState in scc)
{
int rowCoord = dtmcState2Number[dtmcState];
//update every valued rows elements
var compressedRow = new SortedDictionary<int, double> {{rowCoord, 1}};
foreach (KeyValuePair<double, DTMCState> pair in dtmcState.Transitions)
{
int colCoord = dtmcState2Number[pair.Value];
if(colCoord==rowCoord)
{
compressedRow[rowCoord] += -pair.Key;
}else
{
compressedRow.Add(colCoord, -pair.Key);
}
}
var row = new Row(new List<double>(compressedRow.Values), new List<int>(compressedRow.Keys)) { diag = compressedRow[rowCoord], diagCol = rowCoord };
matrix.Rows.Add(row);
//update diagnoal elements
}
return matrix;
}
public static SparseMatrix GaussianJordenElimination(SparseMatrix smatrix)
{
//int r = smatrix.Nrows;
//for (int i = 0; i < r; i++)
//{
// //row value divide pivot element
// var currentRow = smatrix.Rows[i];
// if (Math.Abs(currentRow.diag) > EPSILON)
// {
// if (Math.Abs(currentRow.diag - 1) > EPSILON)
// {
// for (int k = 0; k < currentRow.val.Count; k++)
// {
// currentRow.val[k] = currentRow.val[k]/currentRow.diag;
// }
// }
// var colIndexCurrentRow = currentRow.col.BinarySearch(i);
// //using current row to deduct every other rows in smatrix if corresponding element in row i is not zero
// for (int j = 0; j < r; j++)
// {
// if(j==i)
// {
// continue;
// }
// var pivotRow = smatrix.Rows[j];
// int colIndexPivot = pivotRow.col.BinarySearch(i);
// if (colIndexPivot >= 0 && Math.Abs(pivotRow.val[colIndexPivot] - 0) > EPSILON)
// //index of col for column value in dense matrix equal to pivot element. if value is zero, it will not be found
// {
// double t = -pivotRow.val[colIndexPivot];
// //var hashset1 = new HashSet<int>(pivotRow.col);
// //hashset1.UnionWith(new HashSet<int>(currentRow.col));
// var r3 = new Row
// {
// diag = pivotRow.diag,
// diagCol = pivotRow.diagCol,
// // val = new List<double>(hashset1.Count),
// // col = hashset1.ToList(),
// };
// //foreach (int i1 in hashset1)
// //{
// // colValuePair.Add(i1,0);
// //}
// //add elements in colValuePair
// var hashset1 = new HashSet<int>();
// for (int inneri = colIndexCurrentRow; inneri < currentRow.col.Count; inneri++)
// {
// hashset1.Add(currentRow.col[inneri]);
// }
// //add workingRow to r3
// var hashset2 = new HashSet<int>();
// for (int inneri =colIndexPivot; inneri < pivotRow.col.Count; inneri++)
// {
// hashset2.Add(pivotRow.col[inneri]);
// }
// hashset2.UnionWith(hashset1);
// var colValuePair = new SortedDictionary<int, double>();
// foreach (int i1 in hashset2)
// {
// colValuePair.Add(i1,0);
// }
// //add currentRow*t to r3
// //inneri starts from colValue as it only needs to update elements after colValue
// for (int inneri = colIndexCurrentRow; inneri < currentRow.col.Count; inneri++)
// {
// colValuePair[currentRow.col[inneri]] += currentRow.val[inneri]*t;
// }
// //add workingRow to r3
// for (int inneri = colIndexPivot; inneri < pivotRow.col.Count; inneri++)
// {
// colValuePair[pivotRow.col[inneri]] += pivotRow.val[inneri];
// }
// //remove new introduced zeros //Comments: this is not productive.
// //var hashsetZeros = new HashSet<int>();
// //foreach (KeyValuePair<int, double> keyValuePair in colValuePair)
// //{
// // if (Math.Abs(keyValuePair.Value) < EPSILON)
// // {
// // hashsetZeros.Add(keyValuePair.Key);
// // }
// //}
// //foreach (int hashsetZero in hashsetZeros)
// //{
// // colValuePair.Remove(hashsetZero);
// //}
// r3.col = new List<int>(colValuePair.Keys);
// r3.val = new List<double>(colValuePair.Values);
// //update diag elements in that row. After row adding, the pivot element/diag info is redundant.
// // r3.diag = r3.col.Contains(r3.diagCol) ? colValuePair[r3.diagCol] : 0;
// smatrix.Rows[j] = r3;
// Debug.WriteLine(smatrix);
// }
// }
// }
//}
//return smatrix;
//the algo can be simplified because of the property for this matrix. The pivot position is positive and nozero.
//we also assume the first element in the column gives the right index (pivot colum index)
//for each elimiantion operation
//there will no redundant row, therefore, after elimiantion, there will no be the case for all elements in a row being
//zeros
int r = smatrix.Nrows;
for (int i = 0; i < r; i++)
{
//row value divide pivot element
var currentRow = smatrix.Rows[i];
//if (Math.Abs(currentRow.diag) > EPSILON)
if(currentRow.col[0]==i) //assert current.Row.col.count>0;
{
if (Math.Abs(currentRow.val[0] - 1) > EPSILON)
{
for (int k = 1; k < currentRow.val.Count; k++)
{
currentRow.val[k] = currentRow.val[k] / currentRow.val[0];
}
}
//remove the pivot position element, dia, diacol is redundant now and remove them
currentRow.col.RemoveAt(0);
currentRow.val.RemoveAt(0);
// var colIndexCurrentRow = currentRow.col.BinarySearch(i); //by right, this should always be the first element in the row
// var colIndexCurrentRow = currentRow.col[0];
//using current row to deduct every other rows in smatrix if corresponding element in row i is not zero
for (int j = 0; j < r; j++)
{
if (j == i)
{
continue;
}
var pivotRow = smatrix.Rows[j];
//int colIndexPivot = pivotRow.col.BinarySearch(i);
//int colIndexPivot = pivotRow.col[0];
// if (colIndexPivot >= 0 && Math.Abs(pivotRow.val[colIndexPivot] - 0) > EPSILON)
if(pivotRow.col[0]==i) //this actually guarantees the value nonzero,
//index of col for column value in dense matrix equal to pivot element. if value is zero, it will not be found
{
double t = -pivotRow.val[0];
pivotRow.col.RemoveAt(0);
pivotRow.val.RemoveAt(0);
//diag, diagcol are also redundant.
//var hashset1 = new HashSet<int>(pivotRow.col);
//hashset1.UnionWith(new HashSet<int>(currentRow.col));
var r3 = new Row
{
diag = pivotRow.diag,
diagCol = pivotRow.diagCol,
// val = new List<double>(hashset1.Count),
// col = hashset1.ToList(),
};
//add elements in colValuePair
var hashset1 = new HashSet<int>(currentRow.col);
hashset1.UnionWith(new HashSet<int>(pivotRow.col));
var colValuePair = new SortedDictionary<int, double>();
foreach (int i1 in hashset1)
{
colValuePair.Add(i1,0);
}
//add currentRow*t to r3
//inneri starts from colValue as it only needs to update elements after colValue
for (int inneri = 0; inneri < currentRow.col.Count; inneri++)
{
if (Math.Abs(currentRow.val[inneri]) > EPSILON) //make sure zero is not added
{
colValuePair[currentRow.col[inneri]] += currentRow.val[inneri] * t;
}
}
//add workingRow to r3
for (int inneri = 0; inneri < pivotRow.col.Count; inneri++)
{
double m = colValuePair[pivotRow.col[inneri]] + pivotRow.val[inneri];
if (Math.Abs(m) > EPSILON) //make sure zero is not added
{
colValuePair[pivotRow.col[inneri]] = m;
}
}
r3.col = new List<int>(colValuePair.Keys);
r3.val = new List<double>(colValuePair.Values);
//update diag elements in that row. After row adding, the pivot element/diag info is redundant.
// r3.diag = r3.col.Contains(r3.diagCol) ? colValuePair[r3.diagCol] : 0;
smatrix.Rows[j] = r3;
Debug.WriteLine(smatrix);
}
}
}
}
return smatrix;
}
