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#include <RadialStripTopology.h>
Public Member Functions | |
| float | angularWidth () const |
| float | centreToIntersection () const |
| virtual int | channel (const LocalPoint &) const |
| float | detHeight () const |
| virtual LocalError | localError (float strip, float stripErr2) const |
| virtual LocalError | localError (const MeasurementPoint &, const MeasurementError &) const |
| virtual float | localPitch (const LocalPoint &) const |
| virtual LocalPoint | localPosition (float strip) const |
| virtual LocalPoint | localPosition (const MeasurementPoint &) const |
| virtual float | localStripLength (const LocalPoint &) const |
| virtual MeasurementError | measurementError (const LocalPoint &, const LocalError &) const |
| virtual MeasurementPoint | measurementPosition (const LocalPoint &) const |
| virtual int | nearestStrip (const LocalPoint &) const |
| virtual int | nstrips () const |
| float | originToIntersection () const |
| float | phiOfOneEdge () const |
| virtual float | phiPitch (void) const |
| virtual float | pitch () const |
| RadialStripTopology (int ns, float aw, float dh, float r, int yAx=1, float yMid=0.) | |
| virtual float | strip (const LocalPoint &) const |
| virtual float | stripAngle (float strip) const |
| virtual float | stripLength () const |
| float | xOfStrip (int strip, float y) const |
| int | yAxisOrientation () const |
| float | yCentreOfStripPlane () const |
| float | yDistanceToIntersection (float y) const |
| float | yExtentOfStripPlane () const |
| virtual | ~RadialStripTopology () |
Private Attributes | |
| float | theAngularWidth |
| float | theCentreToIntersection |
| float | theDetHeight |
| int | theNumberOfStrips |
| float | thePhiOfOneEdge |
| int | theYAxisOrientation |
| float | yCentre |
Friends | |
| std::ostream & | operator<< (std::ostream &, const RadialStripTopology &) |
A StripTopology in which the component strips subtend a constant angular width, and, if projected, intersect at a point.
WARNING! Wherever 'float strip' is used the units of 'strip' are angular widths of each strip. The range is from 0.0 at the extreme edge of the 'first' strip at one edge of the detector, to nstrip*angular width at the other edge.
The centre of the first strip is at strip = 0.5
The centre of the last strip is at strip = 0.5 + (nstrip-1)
This is for consistency with CommonDet usage of 'float strip' (but where units are strip pitch rather than strip angular width.)
WARNING! If the mid-point along local y of the plane of strips does not correspond to the local coordinate origin, set the final ctor argument appropriately.
Definition at line 26 of file RadialStripTopology.h.
| RadialStripTopology::RadialStripTopology | ( | int | ns, |
| float | aw, | ||
| float | dh, | ||
| float | r, | ||
| int | yAx = 1, |
||
| float | yMid = 0. |
||
| ) |
Constructor from:
| ns | number of strips |
| aw | angular width of a strip |
| dh | detector height (usually 2 x apothem of TrapezoidalPlaneBounds) |
| r | radial distance from symmetry centre of detector to the point at which the outer edges of the two extreme strips (projected) intersect. |
| yAx | orientation of local y axis: 1 means pointing from the smaller side of the module to the larger side (along apothem), and -1 means in the opposite direction, i.e. from the larger side along the apothem to the smaller side. Default value is 1. |
| yMid | local y offset if mid-point of detector (strip plane) does not coincide with local origin. This decouples the extent of strip plane from the boundary of the detector in which the RST is embedded. |
Definition at line 9 of file RadialStripTopology.cc.
References LogTrace, theAngularWidth, theNumberOfStrips, thePhiOfOneEdge, theYAxisOrientation, and yCentre.
: theNumberOfStrips(ns), theAngularWidth(aw), theDetHeight(dh), theCentreToIntersection(r), theYAxisOrientation(yAx), yCentre( yMid) { // Angular offset of extreme edge of detector, so that angle is // zero for a strip lying along local y axis = long symmetry axis of plane of strips thePhiOfOneEdge = -(0.5*theNumberOfStrips) * theAngularWidth * yAx; LogTrace("RadialStripTopology") << "RadialStripTopology: constructed with" << " strips = " << ns << " width = " << aw << " rad " << " det_height = " << dh << " ctoi = " << r << " phi_edge = " << thePhiOfOneEdge << " rad " << " y_ax_ori = " << theYAxisOrientation << " y_det_centre = " << yCentre << "\n"; }
| virtual RadialStripTopology::~RadialStripTopology | ( | ) | [inline, virtual] |
| float RadialStripTopology::angularWidth | ( | ) | const [inline] |
Angular width of a each strip
Definition at line 169 of file RadialStripTopology.h.
References theAngularWidth.
Referenced by FWRecoGeometryESProducer::addCSCGeometry(), TrackerValidationVariables::fillHitQuantities(), StripCPE::fillParam(), localError(), localPitch(), OffsetRadialStripTopology::localPosition(), measurementError(), measurementPosition(), OffsetRadialStripTopology::OffsetRadialStripTopology(), phiPitch(), OffsetRadialStripTopology::strip(), strip(), OffsetRadialStripTopology::stripAngle(), stripAngle(), and ValidateGeometry::validateCSCLayerGeometry().
{ return theAngularWidth;}
| float RadialStripTopology::centreToIntersection | ( | ) | const [inline] |
Distance from the intersection of the projections of the extreme edges of the two extreme strips to the symmetry centre of the plane of strips.
Definition at line 191 of file RadialStripTopology.h.
References theCentreToIntersection.
Referenced by FWRecoGeometryESProducer::addCSCGeometry(), localError(), operator<<(), and ValidateGeometry::validateCSCLayerGeometry().
{ return theCentreToIntersection; }
| int RadialStripTopology::channel | ( | const LocalPoint & | lp | ) | const [virtual] |
Channel number corresponding to a given LocalPoint.
This is effectively an integer version of strip(), with range 0 to nstrips-1.
LocalPoints outside the detector strip plane will be considered as contributing to the edge channels 0 or nstrips-1.
Implements Topology.
Reimplemented in OffsetRadialStripTopology, CSCGangedStripTopology, and CSCUngangedStripTopology.
Definition at line 28 of file RadialStripTopology.cc.
References min, strip(), and theNumberOfStrips.
{ return std::min( int( strip(lp) ), theNumberOfStrips-1 ) ;}
| float RadialStripTopology::detHeight | ( | ) | const [inline] |
Length of long symmetry axis of plane of strips
Definition at line 179 of file RadialStripTopology.h.
References theDetHeight.
Referenced by TrackerValidationVariables::fillHitQuantities(), localError(), OffsetRadialStripTopology::localPosition(), localPosition(), localStripLength(), measurementError(), measurementPosition(), and operator<<().
{ return theDetHeight;}
| LocalError RadialStripTopology::localError | ( | const MeasurementPoint & | mp, |
| const MeasurementError & | me | ||
| ) | const [virtual] |
LocalError for a given MeasurementPoint with known MeasurementError. This may be used in Kalman filtering and hence must allow possible correlations between the components.
Implements Topology.
Definition at line 86 of file RadialStripTopology.cc.
References angularWidth(), alignmentValidation::c1, centreToIntersection(), funct::cos(), detHeight(), phi, dttmaxenums::R, indexGen::s2, funct::sin(), stripAngle(), MeasurementError::uu(), MeasurementError::uv(), MeasurementError::vv(), PV2DBase< T, PVType, FrameType >::x(), xy(), PV2DBase< T, PVType, FrameType >::y(), and yAxisOrientation().
{
const double
phi(stripAngle(mp.x())), s1(std::sin(phi)), c1(std::cos(phi)),
cs(s1*c1), s2(s1*s1), c2(1-s2), // rotation matrix
T( angularWidth() * ( centreToIntersection() + yAxisOrientation()*mp.y()*detHeight()) / c1 ), // tangential measurement unit (local pitch)
R( detHeight()/ c1 ), // radial measurement unit (strip length)
tt( me.uu() * T*T ), // tangential sigma^2
rr( me.vv() * R*R ), // radial sigma^2
tr( me.uv() * T*R ),
xx( c2*tt + 2*cs*tr + s2*rr ),
yy( s2*tt - 2*cs*tr + c2*rr ),
xy( cs*( rr - tt ) + tr*( c2 - s2 ) );
return LocalError( xx, xy, yy );
}
| LocalError RadialStripTopology::localError | ( | float | strip, |
| float | stripErr2 | ||
| ) | const [virtual] |
LocalError for a pure strip measurement, where 'strip' is the (float) position (a 'phi' angle wrt y axis) and stripErr2 is the sigma-squared. Both quantities are expressed in units of theAngularWidth of a strip.
Implements StripTopology.
Definition at line 70 of file RadialStripTopology.cc.
References angularWidth(), centreToIntersection(), detHeight(), f, phi, funct::pow(), stripAngle(), funct::tan(), and xy().
{
const double
phi(stripAngle(strip)), t1(std::tan(phi)), t2(t1*t1),
// s1(std::sin(phi)), c1(std::cos(phi)),
// cs(s1*c1), s2(s1*s1), c2(1-s2), // rotation matrix
tt( stripErr2 * std::pow( centreToIntersection()*angularWidth() ,2.f) ), // tangential sigma^2 *c2
rr( std::pow(detHeight(), 2.f) * (1.f/12.f) ), // radial sigma^2( uniform prob density along strip) *c2
xx( tt + t2*rr ),
yy( t2*tt + rr ),
xy( t1*( rr - tt ) );
return LocalError( xx, xy, yy );
}
| float RadialStripTopology::localPitch | ( | const LocalPoint & | lp | ) | const [virtual] |
Pitch (strip width) at a given LocalPoint.
BEWARE: are you sure you really want to call this for a RadialStripTopology?
Implements StripTopology.
Definition at line 122 of file RadialStripTopology.cc.
References angularWidth(), funct::cos(), f, min, nstrips(), funct::pow(), funct::sin(), strip(), stripAngle(), PV3DBase< T, PVType, FrameType >::y(), and yDistanceToIntersection().
Referenced by StripCPE::fillParam(), and CSCLayerGeometry::stripPitch().
{
// The local pitch is the local x width of the strip at the local (x,y)
const int istrip = std::min(nstrips(), static_cast<int>(strip(lp)) + 1); // which strip number
const float fangle = stripAngle(static_cast<float>(istrip) - 0.5); // angle of strip centre
return
yDistanceToIntersection( lp.y() ) * std::sin(angularWidth()) /
std::pow( std::cos(fangle-0.5f*angularWidth()), 2.f);
}
| LocalPoint RadialStripTopology::localPosition | ( | const MeasurementPoint & | mp | ) | const [virtual] |
LocalPoint for a given MeasurementPoint
What's a MeasurementPoint?
In analogy with that used with TrapezoidalStripTopology objects, a MeasurementPoint is a 2-dim object.
The first dimension measures the angular position wrt central line of symmetry of detector, in units of strip (angular) widths (range 0 to total angle subtended by a detector).
The second dimension measures the fractional position along the strip (range -0.5 to +0.5).
BEWARE! The components are not Cartesian.
Implements Topology.
Reimplemented in OffsetRadialStripTopology.
Definition at line 56 of file RadialStripTopology.cc.
References detHeight(), stripAngle(), funct::tan(), ExpressReco_HICollisions_FallBack::x, PV2DBase< T, PVType, FrameType >::x(), ExpressReco_HICollisions_FallBack::y, PV2DBase< T, PVType, FrameType >::y(), yAxisOrientation(), yCentreOfStripPlane(), and yDistanceToIntersection().
{
const float // y = (L/cos(phi))*mp.y()*cos(phi)
y( mp.y()*detHeight() + yCentreOfStripPlane() ),
x( yAxisOrientation() * yDistanceToIntersection( y ) * std::tan ( stripAngle( mp.x() ) ) );
return LocalPoint( x, y );
}
| LocalPoint RadialStripTopology::localPosition | ( | float | strip | ) | const [virtual] |
LocalPoint on x axis for given 'strip' 'strip' is a float in units of the strip (angular) width
Implements StripTopology.
Reimplemented in OffsetRadialStripTopology.
Definition at line 52 of file RadialStripTopology.cc.
References originToIntersection(), stripAngle(), funct::tan(), and yAxisOrientation().
{
return LocalPoint( yAxisOrientation() * originToIntersection() * tan( stripAngle(strip) ), 0 );
}
| float RadialStripTopology::localStripLength | ( | const LocalPoint & | lp | ) | const [virtual] |
Length of a strip passing through a given LocalPpoint
Implements StripTopology.
Definition at line 36 of file RadialStripTopology.cc.
References detHeight(), f, funct::pow(), mathSSE::sqrt(), PV3DBase< T, PVType, FrameType >::x(), PV3DBase< T, PVType, FrameType >::y(), and yDistanceToIntersection().
Referenced by TrackerValidationVariables::fillHitQuantities().
| MeasurementError RadialStripTopology::measurementError | ( | const LocalPoint & | p, |
| const LocalError & | e | ||
| ) | const [virtual] |
Implements Topology.
Definition at line 104 of file RadialStripTopology.cc.
References angularWidth(), detHeight(), f, funct::pow(), indexGen::s2, mathSSE::sqrt(), matplotRender::t, PV3DBase< T, PVType, FrameType >::x(), LocalError::xx(), LocalError::xy(), PV3DBase< T, PVType, FrameType >::y(), yAxisOrientation(), yDistanceToIntersection(), and LocalError::yy().
Referenced by TrackerValidationVariables::fillHitQuantities().
{
const double
yHitToInter(yDistanceToIntersection(p.y())),
t(yAxisOrientation() * p.x() / yHitToInter), // tan(strip angle)
cs(t/(1+t*t)), s2(t*cs), c2(1-s2), // rotation matrix
T2( 1./(std::pow(angularWidth(),2.f) * ( std::pow(p.x(),2.f) + std::pow(yHitToInter,2)) )), // 1./tangential measurement unit (local pitch) ^2
R2( c2/std::pow(detHeight(),2.f) ), // 1./ radial measurement unit (strip length) ^2
uu( ( c2*e.xx() - 2*cs*e.xy() + s2*e.yy() ) * T2 ),
vv( ( s2*e.xx() + 2*cs*e.xy() + c2*e.yy() ) * R2 ),
uv( ( cs*( e.xx() - e.yy() ) + e.xy()*( c2 - s2 ) ) * std::sqrt (T2*R2) );
return MeasurementError(uu, uv, vv);
}
| MeasurementPoint RadialStripTopology::measurementPosition | ( | const LocalPoint & | lp | ) | const [virtual] |
Implements Topology.
Reimplemented in OffsetRadialStripTopology.
Definition at line 63 of file RadialStripTopology.cc.
References angularWidth(), detHeight(), phi, phiOfOneEdge(), PV3DBase< T, PVType, FrameType >::x(), PV3DBase< T, PVType, FrameType >::y(), yAxisOrientation(), yCentreOfStripPlane(), and yDistanceToIntersection().
Referenced by TrackerValidationVariables::fillHitQuantities().
{
const float // phi is [pi/2 - conventional local phi], use atan2(x,y) rather than atan2(y,x)
phi( yAxisOrientation() * std::atan2( lp.x(), yDistanceToIntersection( lp.y() ) ));
return MeasurementPoint( yAxisOrientation()*( phi-phiOfOneEdge() ) / angularWidth(),
( lp.y() - yCentreOfStripPlane() ) / detHeight() );
}
| int RadialStripTopology::nearestStrip | ( | const LocalPoint & | lp | ) | const [virtual] |
| virtual int RadialStripTopology::nstrips | ( | ) | const [inline, virtual] |
Total number of strips
Implements StripTopology.
Definition at line 130 of file RadialStripTopology.h.
References theNumberOfStrips.
Referenced by localPitch(), nearestStrip(), CSCLayerGeometry::numberOfStrips(), operator<<(), OffsetRadialStripTopology::strip(), and strip().
{ return theNumberOfStrips; }
| float RadialStripTopology::originToIntersection | ( | ) | const [inline] |
(y) distance from intersection of the projections of the strips to the local coordinate origin. Same as centreToIntersection() if symmetry centre of strip plane coincides with local origin.
Definition at line 198 of file RadialStripTopology.h.
References theCentreToIntersection, and yCentre.
Referenced by CSCStripTopology::equationOfStrip(), TrackerValidationVariables::fillHitQuantities(), OffsetRadialStripTopology::localPosition(), localPosition(), OffsetRadialStripTopology::strip(), OffsetRadialStripTopology::toLocal(), OffsetRadialStripTopology::toPrime(), and yDistanceToIntersection().
{ return (theCentreToIntersection - yCentre); }
| float RadialStripTopology::phiOfOneEdge | ( | ) | const [inline] |
Convenience function to access azimuthal angle of extreme edge of first strip measured relative to long symmetry axis of the plane of strips.
WARNING! This angle is measured clockwise from the local y axis which means it is in the conventional azimuthal phi plane, but azimuth is of course measured from local x axis not y. The range of this angle is -(full angle)/2 to +(full angle)/2.
where (full angle) = nstrips() * angularWidth().
Definition at line 212 of file RadialStripTopology.h.
References thePhiOfOneEdge.
Referenced by FWRecoGeometryESProducer::addCSCGeometry(), OffsetRadialStripTopology::localPosition(), measurementPosition(), operator<<(), OffsetRadialStripTopology::strip(), strip(), OffsetRadialStripTopology::stripAngle(), stripAngle(), and ValidateGeometry::validateCSCLayerGeometry().
{ return thePhiOfOneEdge; }
| virtual float RadialStripTopology::phiPitch | ( | void | ) | const [inline, virtual] |
Phi pitch of each strip (= angular width!)
Definition at line 174 of file RadialStripTopology.h.
References angularWidth().
Referenced by operator<<(), and CSCLayerGeometry::stripPhiPitch().
{ return angularWidth(); }
| float RadialStripTopology::pitch | ( | ) | const [virtual] |
BEWARE: calling pitch() throws an exception.
Pitch is conventional name for width of something, but this is not sensible for a RadialStripTopology since strip widths vary with local y. Use localPitch(.) instead.
Implements StripTopology.
Definition at line 120 of file RadialStripTopology.cc.
{ throw Genexception("RadialStripTopology::pitch() called - makes no sense, use localPitch(.) instead."); return 0.;}
| float RadialStripTopology::strip | ( | const LocalPoint & | lp | ) | const [virtual] |
Strip in which a given LocalPoint lies. This is a float which represents the fractional strip position within the detector.
Returns zero if the LocalPoint falls at the extreme low edge of the detector or BELOW, and float(nstrips) if it falls at the extreme high edge or ABOVE.
Implements StripTopology.
Reimplemented in OffsetRadialStripTopology.
Definition at line 45 of file RadialStripTopology.cc.
References angularWidth(), max(), min, nstrips(), phi, phiOfOneEdge(), PV3DBase< T, PVType, FrameType >::x(), PV3DBase< T, PVType, FrameType >::y(), yAxisOrientation(), and yDistanceToIntersection().
Referenced by channel(), localPitch(), nearestStrip(), and SiClusterTranslator::produce().
{
const float // phi is measured from y axis --> sign of angle is sign of x * yAxisOrientation --> use atan2(x,y), not atan2(y,x)
phi( std::atan2( lp.x(), yDistanceToIntersection( lp.y() ) )),
aStrip( ( phi - yAxisOrientation() * phiOfOneEdge() )/angularWidth());
return std::max(float(0), std::min( (float)nstrips(), aStrip ));
}
| float RadialStripTopology::stripAngle | ( | float | strip | ) | const [virtual] |
Angle between strip and symmetry axis (=local y axis) for given strip.
This is like a phi angle but measured clockwise from y axis rather than counter clockwise from x axis. Note that 'strip' is a float with a continuous range from 0 to float(nstrips) to cover the whole detector, and the centres of strips correspond to half-integer values 0.5, 1.5, ..., nstrips-0.5 whereas values 1, 2, ... nstrips correspond to the upper phi edges of the strips.
Implements StripTopology.
Reimplemented in OffsetRadialStripTopology.
Definition at line 32 of file RadialStripTopology.cc.
References angularWidth(), phiOfOneEdge(), and yAxisOrientation().
Referenced by TrackerValidationVariables::fillHitQuantities(), localError(), localPitch(), localPosition(), and xOfStrip().
{ return phiOfOneEdge() + yAxisOrientation() * strip * angularWidth() ;}
| virtual float RadialStripTopology::stripLength | ( | ) | const [inline, virtual] |
Height of detector (= length of long symmetry axis of the plane of strips).
Implements StripTopology.
Definition at line 135 of file RadialStripTopology.h.
References theDetHeight.
Referenced by StripCPE::fillParam().
{ return theDetHeight; }
| float RadialStripTopology::xOfStrip | ( | int | strip, |
| float | y | ||
| ) | const |
Local x where centre of strip intersects input local y
'strip' should be in range 1 to nstrips()
Definition at line 40 of file RadialStripTopology.cc.
References stripAngle(), funct::tan(), yAxisOrientation(), and yDistanceToIntersection().
Referenced by CSCLayerGeometry::xOfStrip().
{
return
yAxisOrientation() * yDistanceToIntersection( y ) * std::tan( stripAngle(static_cast<float>(strip) - 0.5 ) );
}
| int RadialStripTopology::yAxisOrientation | ( | ) | const [inline] |
y axis orientation, 1 means detector width increases with local y
Definition at line 228 of file RadialStripTopology.h.
References theYAxisOrientation.
Referenced by FWRecoGeometryESProducer::addCSCGeometry(), localError(), localPosition(), measurementError(), measurementPosition(), operator<<(), strip(), stripAngle(), ValidateGeometry::validateCSCLayerGeometry(), xOfStrip(), and yDistanceToIntersection().
{ return theYAxisOrientation; }
| float RadialStripTopology::yCentreOfStripPlane | ( | ) | const [inline] |
Offset in local y between midpoint of detector (strip plane) extent and local origin
Definition at line 233 of file RadialStripTopology.h.
References yCentre.
Referenced by FWRecoGeometryESProducer::addCSCGeometry(), OffsetRadialStripTopology::localPosition(), localPosition(), measurementPosition(), operator<<(), ValidateGeometry::validateCSCLayerGeometry(), and CSCStripTopology::yLimitsOfStripPlane().
{ return yCentre; }
| float RadialStripTopology::yDistanceToIntersection | ( | float | y | ) | const |
Distance in local y from a hit to the point of intersection of projected strips
Definition at line 34 of file RadialStripTopology.cc.
References originToIntersection(), and yAxisOrientation().
Referenced by localPitch(), localPosition(), localStripLength(), measurementError(), measurementPosition(), strip(), and xOfStrip().
{ return yAxisOrientation()*y + originToIntersection() ;}
| float RadialStripTopology::yExtentOfStripPlane | ( | ) | const [inline] |
y extent of strip plane
Definition at line 184 of file RadialStripTopology.h.
References theDetHeight.
Referenced by CSCStripTopology::yLimitsOfStripPlane().
{ return theDetHeight; } // same as detHeight()
| std::ostream& operator<< | ( | std::ostream & | os, |
| const RadialStripTopology & | rst | ||
| ) | [friend] |
Definition at line 132 of file RadialStripTopology.cc.
{
os << "RadialStripTopology " << std::endl
<< " " << std::endl
<< "number of strips " << rst.nstrips() << std::endl
<< "centre to whereStripsMeet " << rst.centreToIntersection() << std::endl
<< "detector height in y " << rst.detHeight() << std::endl
<< "angular width of strips " << rst.phiPitch() << std::endl
<< "phi of one edge " << rst.phiOfOneEdge() << std::endl
<< "y axis orientation " << rst.yAxisOrientation() << std::endl
<< "y of centre of strip plane " << rst.yCentreOfStripPlane() << std::endl;
return os;
}
float RadialStripTopology::theAngularWidth [private] |
Definition at line 245 of file RadialStripTopology.h.
Referenced by angularWidth(), and RadialStripTopology().
float RadialStripTopology::theCentreToIntersection [private] |
Definition at line 247 of file RadialStripTopology.h.
Referenced by centreToIntersection(), and originToIntersection().
float RadialStripTopology::theDetHeight [private] |
Definition at line 246 of file RadialStripTopology.h.
Referenced by detHeight(), stripLength(), and yExtentOfStripPlane().
int RadialStripTopology::theNumberOfStrips [private] |
Definition at line 244 of file RadialStripTopology.h.
Referenced by channel(), nstrips(), and RadialStripTopology().
float RadialStripTopology::thePhiOfOneEdge [private] |
Definition at line 248 of file RadialStripTopology.h.
Referenced by phiOfOneEdge(), and RadialStripTopology().
int RadialStripTopology::theYAxisOrientation [private] |
Definition at line 249 of file RadialStripTopology.h.
Referenced by RadialStripTopology(), and yAxisOrientation().
float RadialStripTopology::yCentre [private] |
Definition at line 250 of file RadialStripTopology.h.
Referenced by originToIntersection(), RadialStripTopology(), and yCentreOfStripPlane().
1.7.3