int InverseElementTransformation::FindClosestRefPoint(
const Vector& pt, const IntegrationRule &ir)
{
MFEM_VERIFY(T != NULL, "invalid ElementTransformation");
MFEM_VERIFY(pt.Size() == T->GetSpaceDim(), "invalid point");
// Initialize distance and index of closest point
int minIndex = -1;
double minDist = std::numeric_limits<double>::max();
// Check all integration points in ir using the local metric at each point
// induced by the transformation.
Vector dp(T->GetSpaceDim()), dr(T->GetDimension());
const int npts = ir.GetNPoints();
for (int i = 0; i < npts; ++i)
{
const IntegrationPoint &ip = ir.IntPoint(i);
T->Transform(ip, dp);
dp -= pt;
T->SetIntPoint(&ip);
T->InverseJacobian().Mult(dp, dr);
double dist = dr.Norml2();
// double dist = dr.Normlinf();
if (dist < minDist)
{
minDist = dist;
minIndex = i;
}
}
return minIndex;
}
void IsoparametricTransformation::Transform (const IntegrationRule &ir,
DenseMatrix &tr)
{
int dof, n, dim, i, j, k;
dim = PointMat.Height();
dof = FElem->GetDof();
n = ir.GetNPoints();
shape.SetSize(dof);
tr.SetSize(dim, n);
for (j = 0; j < n; j++)
{
FElem -> CalcShape (ir.IntPoint(j), shape);
for (i = 0; i < dim; i++)
{
tr(i, j) = 0.0;
for (k = 0; k < dof; k++)
{
tr(i, j) += PointMat(i, k) * shape(k);
}
}
}
}
int InverseElementTransformation::FindClosestPhysPoint(
const Vector& pt, const IntegrationRule &ir)
{
MFEM_VERIFY(T != NULL, "invalid ElementTransformation");
MFEM_VERIFY(pt.Size() == T->GetSpaceDim(), "invalid point");
DenseMatrix physPts;
T->Transform(ir, physPts);
// Initialize distance and index of closest point
int minIndex = -1;
double minDist = std::numeric_limits<double>::max();
// Check all integration points in ir
const int npts = ir.GetNPoints();
for (int i = 0; i < npts; ++i)
{
double dist = pt.DistanceTo(physPts.GetColumn(i));
if (dist < minDist)
{
minDist = dist;
minIndex = i;
}
}
return minIndex;
}
void IntegrationPointTransformation::Transform (const IntegrationRule &ir1,
IntegrationRule &ir2)
{
int i, n;
n = ir1.GetNPoints();
for (i = 0; i < n; i++)
{
Transform (ir1.IntPoint(i), ir2.IntPoint(i));
}
}