public SparseMatrix BuildLaplaceGraphNomalized(TriMesh mesh)
{
SparseMatrix m = new SparseMatrix(mesh.Vertices.Count,
mesh.Vertices.Count);
foreach (TriMesh.Vertex vertex in mesh.Vertices)
{
foreach (TriMesh.Vertex neigh in vertex.Vertices)
{
double result = -1d / Math.Sqrt(vertex.VertexCount
* neigh.VertexCount);
m.AddValueTo(vertex.Index,
neigh.Index,
result);
}
m.AddValueTo(vertex.Index, vertex.Index, 1);
}
m.SortElement();
return m;
}
public SparseMatrix BuildLaplaceTutte(TriMesh mesh)
{
SparseMatrix m = new SparseMatrix(mesh.Vertices.Count,
mesh.Vertices.Count);
foreach (TriMesh.Vertex vertex in mesh.Vertices)
{
foreach (TriMesh.Vertex neigh in vertex.Vertices)
{
double result = -1d / vertex.VertexCount;
m.AddElementIfNotExist(vertex.Index,
neigh.Index,
result);
}
m.AddValueTo(vertex.Index, vertex.Index, 1);
}
m.SortElement();
return m;
}
public static SparseMatrix BuildMatrixDualL(ref NonManifoldMesh mesh)
{
// build dual Laplacian weight matrix L
int vn = mesh.VertexCount;
int fn = mesh.FaceCount;
SparseMatrix L = new SparseMatrix(fn, vn, 6);
for (int i = 0; i < fn; i++)
{
int f1 = mesh.AdjFF[i][0];
int f2 = mesh.AdjFF[i][1];
int f3 = mesh.AdjFF[i][2];
Vector3D dv = mesh.GetDualPosition(i);
Vector3D dv1 = mesh.GetDualPosition(f1);
Vector3D dv2 = mesh.GetDualPosition(f2);
Vector3D dv3 = mesh.GetDualPosition(f3);
Vector3D u = dv - dv3;
Vector3D v1 = dv1 - dv3;
Vector3D v2 = dv2 - dv3;
Vector3D normal = (v1.Cross(v2)).Normalize();
Matrix3D M = new Matrix3D(v1, v2, normal);
Vector3D coord = M.Inverse() * u;
double alpha;
alpha = 1.0 / 3.0;
for (int j = 0, k = i * 3; j < 3; j++)
L.AddValueTo(i, mesh.FaceIndex[k++], alpha);
alpha = coord[0] / 3.0;
for (int j = 0, k = f1 * 3; j < 3; j++)
L.AddValueTo(i, mesh.FaceIndex[k++], -alpha);
alpha = coord[1] / 3.0;
for (int j = 0, k = f2 * 3; j < 3; j++)
L.AddValueTo(i, mesh.FaceIndex[k++], -alpha);
alpha = (1.0 - coord[0] - coord[1]) / 3.0;
for (int j = 0, k = f3 * 3; j < 3; j++)
L.AddValueTo(i, mesh.FaceIndex[k++], -alpha);
}
L.SortElement();
return L;
}
public static SparseMatrix BuildCurvatureMatrixL(ref NonManifoldMesh mesh)
{
if (mesh == null)
throw new Exception("mesh is null");
int n = mesh.VertexCount;
SparseMatrix L = new SparseMatrix(n, n);
for (int i = 0, j = 0; i < mesh.FaceCount; i++, j += 3)
{
int c1 = mesh.FaceIndex[j];
int c2 = mesh.FaceIndex[j + 1];
int c3 = mesh.FaceIndex[j + 2];
Vector3D v1 = new Vector3D(mesh.VertexPos, c1 * 3);
Vector3D v2 = new Vector3D(mesh.VertexPos, c2 * 3);
Vector3D v3 = new Vector3D(mesh.VertexPos, c3 * 3);
double cot1 = (v2 - v1).Dot(v3 - v1) / (v2 - v1).Cross(v3 - v1).Length();
double cot2 = (v3 - v2).Dot(v1 - v2) / (v3 - v2).Cross(v1 - v2).Length();
double cot3 = (v1 - v3).Dot(v2 - v3) / (v1 - v3).Cross(v2 - v3).Length();
L.AddValueTo(c1, c2, -cot3); L.AddValueTo(c2, c1, -cot3);
L.AddValueTo(c2, c3, -cot1); L.AddValueTo(c3, c2, -cot1);
L.AddValueTo(c3, c1, -cot2); L.AddValueTo(c1, c3, -cot2);
}
double[] voronoiArea=ComputeVoronoiArea(ref mesh);
for (int i = 0; i < n; i++)
{
double sum = 0;
foreach (SparseMatrix.Element e in L.Rows[i])
{
e.value = e.value / (voronoiArea[e.i]*2);
}
foreach (SparseMatrix.Element e in L.Rows[i])
{
sum += e.value;
}
L.AddValueTo(i, i, -sum);
}
L.SortElement();
return L;
}
private ColMatrix BuildMatrixA(List <VertexRecord> records, int[] faceIndex, double[] lapWeight, double[] posWeight, double weightAdjustment)
{
// build backward map
int[] map = new int[mesh.VertexCount];
for (int i = 0; i < records.Count; i++)
{
map[records[i].index] = i;
}
int n = records.Count;
int fn = faceIndex.Length / 3;
SparseMatrix A = new SparseMatrix(2 * n, n);
this.currentArea = new double[n];
for (int i = 0; i < n; i++)
{
currentArea[i] = 0;
}
for (int i = 0, j = 0; i < fn; i++, j += 3)
{
int c1 = faceIndex[j];
int c2 = faceIndex[j + 1];
int c3 = faceIndex[j + 2];
Vector3d v1 = new Vector3d(mesh.VertexPos, c1 * 3);
Vector3d v2 = new Vector3d(mesh.VertexPos, c2 * 3);
Vector3d v3 = new Vector3d(mesh.VertexPos, c3 * 3);
double cot1 = (v2 - v1).Dot(v3 - v1) / (v2 - v1).Cross(v3 - v1).Length();
double cot2 = (v3 - v2).Dot(v1 - v2) / (v3 - v2).Cross(v1 - v2).Length();
double cot3 = (v1 - v3).Dot(v2 - v3) / (v1 - v3).Cross(v2 - v3).Length();
//cot1 = cot2 = cot3 = 1.0;
if (double.IsNaN(cot1))
{
throw new Exception();
}
if (double.IsNaN(cot2))
{
throw new Exception();
}
if (double.IsNaN(cot3))
{
throw new Exception();
}
c1 = map[c1];
c2 = map[c2];
c3 = map[c3];
A.AddValueTo(c2, c2, -cot1); A.AddValueTo(c2, c3, cot1);
A.AddValueTo(c3, c3, -cot1); A.AddValueTo(c3, c2, cot1);
A.AddValueTo(c3, c3, -cot2); A.AddValueTo(c3, c1, cot2);
A.AddValueTo(c1, c1, -cot2); A.AddValueTo(c1, c3, cot2);
A.AddValueTo(c1, c1, -cot3); A.AddValueTo(c1, c2, cot3);
A.AddValueTo(c2, c2, -cot3); A.AddValueTo(c2, c1, cot3);
double area = ((v2 - v1).Cross(v3 - v1)).Length() / 2.0;
currentArea[c1] += area;
currentArea[c2] += area;
currentArea[c3] += area;
}
for (int i = 0; i < n; i++)
{
double tot = 0;
foreach (SparseMatrix.Element e in A.Rows[i])
{
if (e.i != e.j)
{
tot += e.value;
}
}
if (tot > 10000)
{
foreach (SparseMatrix.Element e in A.Rows[i])
{
e.value /= (tot / 10000);
}
}
foreach (SparseMatrix.Element e in A.Rows[i])
{
e.value *= lapWeight[records[i].index] * weightAdjustment;
}
}
// positional constraints
for (int i = 0; i < n; i++)
{
int j = records[i].index;
double weight = posWeight[j] * (currentArea[i] / originalArea[j]);
if (weight <= 0)
{
weight = posWeight[i];
}
A.AddValueTo(i + n, i, weight);
}
A.SortElement();
ColMatrixCreator cmA = new ColMatrixCreator(2 * n, n);
foreach (List <SparseMatrix.Element> r in A.Rows)
{
foreach (SparseMatrix.Element e in r)
{
cmA.AddValueTo(e.i, e.j, e.value);
}
}
return(cmA);
}
private SparseMatrix BuildMatrixA_old(List <VertexRecord> records, int[] faceIndex, double[] lapWeight, double[] posWeight)
{
// build backward map
int[] map = new int[mesh.VertexCount];
for (int i = 0; i < records.Count; i++)
{
map[records[i].index] = i;
}
int n = records.Count;
int fn = faceIndex.Length / 3;
SparseMatrix A = new SparseMatrix(2 * n, n);
for (int i = 0, j = 0; i < fn; i++, j += 3)
{
int c1 = faceIndex[j];
int c2 = faceIndex[j + 1];
int c3 = faceIndex[j + 2];
Vector3d v1 = new Vector3d(mesh.VertexPos, c1 * 3);
Vector3d v2 = new Vector3d(mesh.VertexPos, c2 * 3);
Vector3d v3 = new Vector3d(mesh.VertexPos, c3 * 3);
double cot1 = (v2 - v1).Dot(v3 - v1) / (v2 - v1).Cross(v3 - v1).Length();
double cot2 = (v3 - v2).Dot(v1 - v2) / (v3 - v2).Cross(v1 - v2).Length();
double cot3 = (v1 - v3).Dot(v2 - v3) / (v1 - v3).Cross(v2 - v3).Length();
//cot1 = cot2 = cot3 = 1.0;
if (double.IsNaN(cot1))
{
throw new Exception();
}
if (double.IsNaN(cot2))
{
throw new Exception();
}
if (double.IsNaN(cot3))
{
throw new Exception();
}
c1 = map[c1];
c2 = map[c2];
c3 = map[c3];
A.AddValueTo(c2, c2, -cot1); A.AddValueTo(c2, c3, cot1);
A.AddValueTo(c3, c3, -cot1); A.AddValueTo(c3, c2, cot1);
A.AddValueTo(c3, c3, -cot2); A.AddValueTo(c3, c1, cot2);
A.AddValueTo(c1, c1, -cot2); A.AddValueTo(c1, c3, cot2);
A.AddValueTo(c1, c1, -cot3); A.AddValueTo(c1, c2, cot3);
A.AddValueTo(c2, c2, -cot3); A.AddValueTo(c2, c1, cot3);
}
for (int i = 0; i < n; i++)
{
double tot = 0;
foreach (SparseMatrix.Element e in A.Rows[i])
{
if (e.i != e.j)
{
tot += e.value;
}
}
if (tot > 10000)
{
foreach (SparseMatrix.Element e in A.Rows[i])
{
e.value /= (tot / 10000);
}
}
foreach (SparseMatrix.Element e in A.Rows[i])
{
e.value *= lapWeight[records[i].index];
}
}
// positional constraints
for (int i = 0; i < n; i++)
{
A.AddElement(i + n, i, posWeight[records[i].index]);
}
A.SortElement();
return(A);
}
public SparseMatrix BuildMatrix2N(SparseMatrix L)
{
int n = L.ColumnSize;
SparseMatrix Ld = new SparseMatrix(2 * n, 2 * n);
foreach (List<SparseMatrix.Element> row in L.Rows)
{
foreach (SparseMatrix.Element rowItem in row)
{
int i = rowItem.i;
int j = rowItem.j;
double value = rowItem.value;
Ld.AddValueTo(2 * i, 2 * j, value);
Ld.AddValueTo(2 * i + 1, 2 * j + 1, value);
}
}
return Ld;
}
//public SparseMatrix BuildMatrixArea(TriMesh mesh)
//{
// List<List<TriMesh.Vertex>> bounds = TriMeshUtil.RetrieveBoundaryAllVertex(mesh);
// int n = mesh.Vertices.Count;
// SparseMatrix A = new SparseMatrix(2 * n + 4, 2 * n);
// foreach (List<TriMesh.Vertex> oneBoundary in bounds)
// {
// TriMesh.HalfEdge boundaryStartHF = oneBoundary[0].FindHalfedgeTo(oneBoundary[1]);
// TriMesh.HalfEdge currentHF = boundaryStartHF;
// do
// {
// TriMesh.Vertex Vi = currentHF.FromVertex;
// TriMesh.Vertex Vj = currentHF.ToVertex;
// //Mark UiVj
// A[2 * Vi.Index, 2 * Vj.Index + 1] += 0.5;
// A[2 * Vj.Index + 1, 2 * Vi.Index] += 0.5;
// //Mark VjUi
// A[2 * Vj.Index, 2 * Vi.Index + 1] += -0.5;
// A[2 * Vi.Index + 1, 2 * Vj.Index] += -0.5;
// currentHF = currentHF.Next;
// } while (currentHF != boundaryStartHF);
// }
// return A;
//}
public SparseMatrix BuildMatrix2N(TriMesh mesh)
{
SparseMatrix L = LaplaceManager.Instance.BuildMatrixRigid(mesh);
int n = mesh.Vertices.Count;
SparseMatrix Ld = new SparseMatrix(2 * n, 2 * n);
foreach (List<SparseMatrix.Element> row in L.Rows)
{
foreach (SparseMatrix.Element rowItem in row)
{
int i = rowItem.i;
int j = rowItem.j;
double value = rowItem.value;
Ld.AddValueTo(2 * i, 2 * j, value);
Ld.AddValueTo(2 * i + 1, 2 * j + 1, value);
}
}
return Ld;
}
public SparseMatrix BuildLaplaceMatrixCotBasic(TriMesh mesh)
{
int n = mesh.Vertices.Count;
SparseMatrix L = new SparseMatrix(n, n);
for (int i = 0; i < mesh.Faces.Count; i++)
{
int c1 = mesh.Faces[i].GetVertex(0).Index;
int c2 = mesh.Faces[i].GetVertex(1).Index;
int c3 = mesh.Faces[i].GetVertex(2).Index;
Vector3D v1 = mesh.Faces[i].GetVertex(0).Traits.Position;
Vector3D v2 = mesh.Faces[i].GetVertex(1).Traits.Position;
Vector3D v3 = mesh.Faces[i].GetVertex(2).Traits.Position;
double cot1 = (v2 - v1).Dot(v3 - v1) / (v2 - v1).Cross(v3 - v1).Length();
double cot2 = (v3 - v2).Dot(v1 - v2) / (v3 - v2).Cross(v1 - v2).Length();
double cot3 = (v1 - v3).Dot(v2 - v3) / (v1 - v3).Cross(v2 - v3).Length();
L.AddValueTo(c1, c2, cot3); L.AddValueTo(c2, c1, cot3);
L.AddValueTo(c2, c3, cot1); L.AddValueTo(c3, c2, cot1);
L.AddValueTo(c3, c1, cot2); L.AddValueTo(c1, c3, cot2);
}
return L;
}
public SparseMatrix BuildMatrixDual(TriMesh mesh)
{
int vn = mesh.Vertices.Count;
int fn = mesh.Faces.Count;
SparseMatrix L = new SparseMatrix(fn, vn, 6);
for (int i = 0; i < fn; i++)
{
int f1 = mesh.Faces[i].GetFace(0).Index;
int f2 = mesh.Faces[i].GetFace(1).Index;
int f3 = mesh.Faces[i].GetFace(2).Index;
Vector3D dv = mesh.DualGetVertexPosition(i);
Vector3D dv1 = mesh.DualGetVertexPosition(f1);
Vector3D dv2 = mesh.DualGetVertexPosition(f2);
Vector3D dv3 = mesh.DualGetVertexPosition(f3);
Vector3D u = dv - dv3;
Vector3D v1 = dv1 - dv3;
Vector3D v2 = dv2 - dv3;
Vector3D normal = (v1.Cross(v2)).Normalize();
Matrix3D M = new Matrix3D(v1, v2, normal);
Vector3D coord = M.Inverse() * u;
double alpha;
alpha = 1.0 / 3.0;
L.AddValueTo(i, mesh.Faces[i].GetVertex(0).Index, alpha);
L.AddValueTo(i, mesh.Faces[i].GetVertex(1).Index, alpha);
L.AddValueTo(i, mesh.Faces[i].GetVertex(2).Index, alpha);
alpha = coord[0] / 3.0;
L.AddValueTo(i, mesh.Faces[f1].GetVertex(0).Index, -alpha);
L.AddValueTo(i, mesh.Faces[f1].GetVertex(1).Index, -alpha);
L.AddValueTo(i, mesh.Faces[f1].GetVertex(2).Index, -alpha);
alpha = coord[1] / 3.0;
L.AddValueTo(i, mesh.Faces[f2].GetVertex(0).Index, -alpha);
L.AddValueTo(i, mesh.Faces[f2].GetVertex(1).Index, -alpha);
L.AddValueTo(i, mesh.Faces[f2].GetVertex(2).Index, -alpha);
alpha = (1.0 - coord[0] - coord[1]) / 3.0;
L.AddValueTo(i, mesh.Faces[f3].GetVertex(0).Index, -alpha);
L.AddValueTo(i, mesh.Faces[f3].GetVertex(1).Index, -alpha);
L.AddValueTo(i, mesh.Faces[f3].GetVertex(2).Index, -alpha);
}
L.SortElement();
return L;
}
public SparseMatrix BuildMatrixMass(TriMesh mesh)
{
int n = mesh.Vertices.Count;
SparseMatrix L = new SparseMatrix(n, n);
for (int i = 0; i < mesh.Edges.Count; i++)
{
double face0area = 0;
double face1area = 0;
if (mesh.Edges[i].Face0 != null)
{
face0area = TriMeshUtil.ComputeAreaFace(mesh.Edges[i].Face0);
}
if (mesh.Edges[i].Face1 != null)
{
face1area =TriMeshUtil.ComputeAreaFace(mesh.Edges[i].Face1);
}
L.AddValueTo(mesh.Edges[i].Vertex0.Index,
mesh.Edges[i].Vertex1.Index,
(face0area + face1area) / 12);
L.AddValueTo(mesh.Edges[i].Vertex1.Index,
mesh.Edges[i].Vertex0.Index,
(face0area + face1area) / 12);
}
for (int i = 0; i < n; i++)
{
double sum = 0;
foreach (SparseMatrix.Element e in L.Rows[i])
{
sum += e.value;
}
L.AddValueTo(i, i, sum);
}
L.SortElement();
return L;
}
public SparseMatrix BuildMatrixMeanValue(TriMesh mesh)
{
int n = mesh.Vertices.Count;
SparseMatrix L = BuildAdjacentMatrixVV(mesh);
SparseMatrix D = new SparseMatrix(n, n);
foreach (TriMesh.HalfEdge halfedge in mesh.HalfEdges)
{
TriMesh.Vertex fromJ = halfedge.FromVertex;
TriMesh.Vertex toI = halfedge.ToVertex;
Vector3D jtoI = (toI.Traits.Position - fromJ.Traits.Position).Normalize();
Vector3D alphaToI = (halfedge.Next.ToVertex.Traits.Position
- toI.Traits.Position).Normalize();
Vector3D betaToI = (halfedge.Opposite.Previous.FromVertex.Traits.Position
- toI.Traits.Position).Normalize();
double cosGamaIJ = jtoI.Dot(alphaToI) / (jtoI.Length() * alphaToI.Length());
double cosThetaIJ = jtoI.Dot(betaToI) / (jtoI.Length() * betaToI.Length());
double angelGama = Math.Acos(cosGamaIJ);
double angelTheta = Math.Acos(cosThetaIJ);
double wij = (Math.Tan(angelGama / 2) + Math.Tan(angelTheta / 2))
/ (toI.Traits.Position - fromJ.Traits.Position).Length();
int indexI = toI.Index;
int indexJ = fromJ.Index;
D.AddValueTo(indexI, indexJ, wij);
}
for (int i = 0; i < n; i++)
{
double sum = 0;
foreach (SparseMatrix.Element item in D.Rows[i])
{
sum += item.value;
}
D.AddValueTo(i, i, -sum);
}
return D;
}
public SparseMatrix BuildMatrixCombinatorialGraph(TriMesh mesh)
{
int n = mesh.Vertices.Count;
SparseMatrix W = BuildAdjacentMatrixVV(mesh);
SparseMatrix D = new SparseMatrix(n, n);
for (int i = 0; i < n; i++)
{
double sum = W.Rows[i].Count;
D.AddValueTo(i, i, sum);
}
SparseMatrix K = W.Minus(D);
return K;
}
public SparseMatrix BuildMatrixRigidPositive(TriMesh mesh)
{
int n = mesh.Vertices.Count;
SparseMatrix L = new SparseMatrix(n, n);
for (int i = 0; i < mesh.Faces.Count; i++)
{
int c1 = mesh.Faces[i].GetVertex(0).Index;
int c2 = mesh.Faces[i].GetVertex(1).Index;
int c3 = mesh.Faces[i].GetVertex(2).Index;
Vector3D v1 = mesh.Faces[i].GetVertex(0).Traits.Position;
Vector3D v2 = mesh.Faces[i].GetVertex(1).Traits.Position;
Vector3D v3 = mesh.Faces[i].GetVertex(2).Traits.Position;
double cot1 = (v2 - v1).Dot(v3 - v1) / (v2 - v1).Cross(v3 - v1).Length();
double cot2 = (v3 - v2).Dot(v1 - v2) / (v3 - v2).Cross(v1 - v2).Length();
double cot3 = (v1 - v3).Dot(v2 - v3) / (v1 - v3).Cross(v2 - v3).Length();
L.AddValueTo(c1, c2, cot3 / 2); L.AddValueTo(c2, c1, cot3 / 2);
L.AddValueTo(c2, c3, cot1 / 2); L.AddValueTo(c3, c2, cot1 / 2);
L.AddValueTo(c3, c1, cot2 / 2); L.AddValueTo(c1, c3, cot2 / 2);
}
for (int i = 0; i < n; i++)
{
double sum = 0;
foreach (SparseMatrix.Element e in L.Rows[i])
{
sum += e.value;
}
L.AddValueTo(i, i, -sum);
}
L.SortElement();
return L;
}
private ColMatrix BuildMatrixA(Resolution r, double[] lapWeight, double[] posWeight)
{
// build backward map
int[] map = new int[mesh.VertexCount];
for (int i = 0; i < r.vertexList.Length; i++)
{
map[r.vertexList[i]] = i;
}
int n = r.vertexList.Length;
int fn = r.faceList.Length / 3;
SparseMatrix A = new SparseMatrix(2 * n, n);
for (int i = 0, j = 0; i < fn; i++, j += 3)
{
int c1 = r.faceList[j];
int c2 = r.faceList[j + 1];
int c3 = r.faceList[j + 2];
Vector3d v1 = new Vector3d(mesh.VertexPos, c1 * 3);
Vector3d v2 = new Vector3d(mesh.VertexPos, c2 * 3);
Vector3d v3 = new Vector3d(mesh.VertexPos, c3 * 3);
double cot1 = (v2 - v1).Dot(v3 - v1) / (v2 - v1).Cross(v3 - v1).Length();
double cot2 = (v3 - v2).Dot(v1 - v2) / (v3 - v2).Cross(v1 - v2).Length();
double cot3 = (v1 - v3).Dot(v2 - v3) / (v1 - v3).Cross(v2 - v3).Length();
//cot1 = cot2 = cot3 = 1.0;
if (double.IsNaN(cot1))
{
throw new Exception();
}
if (double.IsNaN(cot2))
{
throw new Exception();
}
if (double.IsNaN(cot3))
{
throw new Exception();
}
c1 = map[c1];
c2 = map[c2];
c3 = map[c3];
A.AddValueTo(c2, c2, -cot1); A.AddValueTo(c2, c3, cot1);
A.AddValueTo(c3, c3, -cot1); A.AddValueTo(c3, c2, cot1);
A.AddValueTo(c3, c3, -cot2); A.AddValueTo(c3, c1, cot2);
A.AddValueTo(c1, c1, -cot2); A.AddValueTo(c1, c3, cot2);
A.AddValueTo(c1, c1, -cot3); A.AddValueTo(c1, c2, cot3);
A.AddValueTo(c2, c2, -cot3); A.AddValueTo(c2, c1, cot3);
}
for (int i = 0; i < n; i++)
{
double tot = 0;
foreach (SparseMatrix.Element e in A.Rows[i])
{
if (e.i != e.j)
{
tot += e.value;
}
}
if (tot > 10000)
{
foreach (SparseMatrix.Element e in A.Rows[i])
{
e.value /= (tot / 10000);
}
}
foreach (SparseMatrix.Element e in A.Rows[i])
{
e.value *= lapWeight[r.vertexList[i]];
}
}
// positional constraints
for (int i = 0; i < n; i++)
{
A.AddElement(i + n, i, posWeight[r.vertexList[i]]);
}
A.SortElement();
ColMatrixCreator cmA = new ColMatrixCreator(2 * n, n);
foreach (List <SparseMatrix.Element> row in A.Rows)
{
foreach (SparseMatrix.Element e in row)
{
cmA.AddValueTo(e.i, e.j, e.value);
}
}
return(cmA);
}