#include <inertia.h>

Inheritance diagram for CenterOfMass:

Collaboration diagram for CenterOfMass:

Public Member Functions
	CenterOfMass (std::set< const ElemGravityOwner * > &elements)

virtual	~CenterOfMass (void)

Protected Member Functions
virtual void	Collect_int (void)

virtual std::ostream &	Output_int (std::ostream &out) const

Protected Attributes
std::set< const ElemGravityOwner * >	elements

doublereal	dMass

Vec3	S

Mat3x3	J

Vec3	X_cm

Vec3	V_cm

Vec3	Omega_cm

Mat3x3	J_cm

Detailed Description

Definition at line 43 of file inertia.h.

Constructor & Destructor Documentation

CenterOfMass::CenterOfMass ( std::set< const ElemGravityOwner * > & elements )

Definition at line 102 of file inertia.cc.

References NO_OP.

                                                                      :
 elements(elements)
 {
         NO_OP;
 }

CenterOfMass::~CenterOfMass ( void )

virtual

Definition at line 108 of file inertia.cc.

References NO_OP.

 {
         NO_OP;
 }

Member Function Documentation

void CenterOfMass::Collect_int ( void )

protectedvirtual

Reimplemented in Inertia.

Definition at line 59 of file inertia.cc.

References ASSERT, Vec3::Cross(), dMass, elements, Mat3x3::IsSymmetric(), J, J_cm, Mat3x3::LDLSolve(), MatCrossCross, Omega_cm, S, Mat3x3::Symm(), V_cm, X_cm, Zero3, and Zero3x3.

Referenced by Inertia::Collect_int().

 {
         dMass = 0.;
         S = Zero3;
         J = Zero3x3;
 
         Vec3 B(Zero3), G(Zero3);
 
         for (std::set<const ElemGravityOwner *>::const_iterator i = elements.begin();
                 i != elements.end(); ++i)
         {
                 dMass += (*i)->dGetM();
                 S += (*i)->GetS();
                 J += (*i)->GetJ();
 
                 B += (*i)->GetB();
                 G += (*i)->GetG();
         }
 
         J_cm = J;
         if (dMass < std::numeric_limits<doublereal>::epsilon()) {
                 X_cm = Zero3;
                 V_cm = Zero3;
                 Omega_cm = Zero3;
                 J_cm = J_cm.Symm();
 
         } else {
                 X_cm = S/dMass;
                 V_cm = B/dMass;
 
                 /*
                  * FIXME: should also rotate it in the principal
                  * reference frame, and log the angles
                  */
                 J_cm += Mat3x3(MatCrossCross, S, X_cm);
                 J_cm = J_cm.Symm();
 
                 ASSERT(J_cm.IsSymmetric()); // NOTE: should be a run time test
                 Omega_cm = J_cm.LDLSolve(G - X_cm.Cross(B));
         }
 }

Here is the call graph for this function:

std::ostream & CenterOfMass::Output_int ( std::ostream & out ) const

protectedvirtual

Reimplemented in Inertia.

Definition at line 47 of file inertia.cc.

References dMass, J, J_cm, Omega_cm, V_cm, and X_cm.

Referenced by Inertia::Output_int().

 {
         return out
                 << "    mass:        " << dMass << std::endl
                 << "    J:           " << J << std::endl
                 << "    Xcg:         " << X_cm << std::endl
                 << "    Jcg:         " << J_cm << std::endl
                 << "    Vcg:         " << V_cm << std::endl
                 << "    Wcg:         " << Omega_cm << std::endl;
 }