PAL10872. Fix 2D aspect ratio according to Nardir Bouhamou's specification

This commit is contained in:
eap 2005-12-12 11:19:33 +00:00
parent 21c1e2551b
commit 8a9307decf

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@ -282,6 +282,10 @@ SMDSAbs_ElementType MinimumAngle::GetType() const
*/
double AspectRatio::GetValue( const TSequenceOfXYZ& P )
{
// According to "Mesh quality control" by Nadir Bouhamau referring to
// Pascal Jean Frey and Paul-Louis George. Maillages, applications aux elements finis.
// Hermes Science publications, Paris 1999 ISBN 2-7462-0024-4
int nbNodes = P.size();
if ( nbNodes < 3 )
@ -289,12 +293,7 @@ double AspectRatio::GetValue( const TSequenceOfXYZ& P )
// Compute lengths of the sides
//double aLen[ nbNodes ];
#ifndef WNT
double aLen [nbNodes];
#else
double* aLen = (double *)new double[nbNodes];
#endif
vector< double > aLen (nbNodes);
for ( int i = 0; i < nbNodes - 1; i++ )
aLen[ i ] = getDistance( P( i + 1 ), P( i + 2 ) );
@ -304,30 +303,43 @@ double AspectRatio::GetValue( const TSequenceOfXYZ& P )
if ( nbNodes == 3 )
{
// Q = alfa * h * p / S, where
//
// alfa = sqrt( 3 ) / 6
// h - length of the longest edge
// p - half perimeter
// S - triangle surface
const double alfa = sqrt( 3. ) / 6.;
double maxLen = Max( aLen[ 0 ], Max( aLen[ 1 ], aLen[ 2 ] ) );
double half_perimeter = ( aLen[0] + aLen[1] + aLen[2] ) / 2.;
double anArea = getArea( P( 1 ), P( 2 ), P( 3 ) );
if ( anArea <= Precision::Confusion() )
return 0.;
double aMaxLen = Max( aLen[ 0 ], Max( aLen[ 1 ], aLen[ 2 ] ) );
static double aCoef = sqrt( 3. ) / 4;
return aCoef * aMaxLen * aMaxLen / anArea;
return alfa * maxLen * half_perimeter / anArea;
}
else
{
double aMinLen = aLen[ 0 ];
double aMaxLen = aLen[ 0 ];
// return aspect ratio of the worst triange which can be built
// taking three nodes of the quadrangle
TSequenceOfXYZ triaPnts(3);
// triangle on nodes 1 3 2
triaPnts(1) = P(1);
triaPnts(2) = P(3);
triaPnts(3) = P(2);
double ar = GetValue( triaPnts );
// triangle on nodes 1 3 4
triaPnts(3) = P(4);
ar = Max ( ar, GetValue( triaPnts ));
// triangle on nodes 1 2 4
triaPnts(2) = P(2);
ar = Max ( ar, GetValue( triaPnts ));
// triangle on nodes 3 2 4
triaPnts(1) = P(3);
ar = Max ( ar, GetValue( triaPnts ));
for(int i = 1; i < nbNodes ; i++ ){
aMinLen = Min( aMinLen, aLen[ i ] );
aMaxLen = Max( aMaxLen, aLen[ i ] );
}
#ifdef WNT
delete [] aLen;
#endif
if ( aMinLen <= Precision::Confusion() )
return 0.;
return aMaxLen / aMinLen;
return ar;
}
}
@ -447,7 +459,7 @@ double AspectRatio3D::GetValue( const TSequenceOfXYZ& P )
double aVolume = getVolume(P);
//double aVolume = getVolume(aLen);
double aHeight = getMaxHeight(aLen);
static double aCoeff = sqrt(6.0)/36.0;
static double aCoeff = sqrt(2.0)/12.0;
aQuality = aCoeff*aHeight*aSumArea/aVolume;
break;
}