public static Vector Flatten(this MatrixByArr mat)
{
#region self-test
if (HDebug.IsDebuggerAttached && selftest_Flatten)
{
selftest_Flatten = false;
MatrixByArr tmat = new double[, ] {
{ 1, 2 }, { 3, 4 }
};
Vector vec0 = new double[] { 1, 2, 3, 4 };
Vector vec1 = tmat.Flatten();
HDebug.AssertAnd(vec0 == vec1);
}
#endregion
int ColSize = mat.ColSize;
int RowSize = mat.RowSize;
Vector vec = new Vector(ColSize * RowSize);
for (int i = 0; i < vec.Size; i++)
{
int c = i / ColSize;
int r = i % ColSize;
vec[i] = mat[c, r];
}
return(vec);
}
public static Vector ClosestPointOnLine(Vector A, Vector B, Vector P, bool segmentClamp)
{
// http://www.gamedev.net/community/forums/topic.asp?topic_id=444154
HDebug.AssertAnd(A.Size == B.Size, B.Size == P.Size);
Vector AP = P - A;
Vector AB = B - A;
double ab2 = LinAlg.VtV(AB, AB);// AB.x*AB.x + AB.y*AB.y;
if (ab2 == 0)
{
return(A.Clone());
}
double ap_ab = LinAlg.VtV(AP, AB); //AP.x*AB.x + AP.y*AB.y;
double t0 = ap_ab / ab2;
double t = t0;
if (segmentClamp)
{
if (t < 0.0)
{
t = 0.0;
}
else if (t > 1.0)
{
t = 1.0;
}
}
Vector Closest = A + AB * t;
HDebug.AssertTolerance(0.000000001, LinAlg.VtV(B - A, P - (A + AB * t0)));
return(Closest);
}
public virtual Vector GetRowVector(int col)
{
HDebug.AssertAnd(0 <= col, col < ColSize);
double[] vec = new double[RowSize];
for (int row = 0; row < RowSize; row++)
{
vec[row] = this[col, row];
}
return(vec);
}
public virtual Vector GetColVector(int row)
{
HDebug.AssertAnd(0 <= row, row < RowSize);
double[] vec = new double[ColSize];
for (int col = 0; col < ColSize; col++)
{
vec[col] = this[col, row];
}
return(vec);
}
public static Vector[] ClosestPointOnLine(IList <Vector> As, IList <Vector> Bs, IList <Vector> Ps, bool segmentClamp)
{
HDebug.AssertAnd(As.Count == Bs.Count, Bs.Count == Ps.Count);
Vector[] closests = new Vector[As.Count];
for (int i = 0; i < As.Count; i++)
{
closests[i] = ClosestPointOnLine(As[i], Bs[i], Ps[i], segmentClamp);
}
return(closests);
}
public static List <Vector> ClosestPointOnLine2(IList <Vector> LineBase, IList <Vector> LineDirect, IList <Vector> Points, bool segmentClamp)
{
HDebug.AssertAnd(LineBase.Count == LineDirect.Count, LineDirect.Count == Points.Count);
List <Vector> closests = new List <Vector>(LineBase.Count);
for (int i = 0; i < LineBase.Count; i++)
{
closests.Add(ClosestPointOnLine(LineBase[i], LineBase[i] + LineDirect[i], Points[i], segmentClamp));
}
HDebug.Assert(closests.Count == LineBase.Count);
return(closests);
}
public VectorSparse <T> GetRowVector(int col)
{
HDebug.AssertAnd(0 <= col, col < RowSize);
VectorSparse <T> vec = new VectorSparse <T>(RowSize, GetDefault: GetDefault);
if (diagonal[col] != null)
{
vec[col] = diagonal[col];
}
foreach (var r_val in offdiagonal[col])
{
int r = r_val.Key;
T val = r_val.Value;
vec[r] = val;
}
return(vec);
}
public static Vector HReshapeToColVector(this IMatrix <double> _this)
{
if (HDebug.IsDebuggerAttached && selftest_ToColVector)
#region self-test
{
selftest_ToColVector = false;
MatrixByArr mat = new double[, ] {
{ 1, 2 }, { 3, 4 }
};
Vector colvec0 = new double[] { 1, 3, 2, 4 };
Vector colvec1 = mat.HReshapeToColVector();
HDebug.AssertAnd(colvec0 == colvec1);
}
#endregion
Vector vec = new double[_this.ColSize * _this.RowSize];
for (int c = 0; c < _this.ColSize; c++)
{
for (int r = 0; r < _this.RowSize; r++)
{
vec[c + r * _this.ColSize] = _this[c, r];
}
}
return(vec);
}
