/// Multiplies a vector of spatial momenta by a vector
VectorNd& mult(const vector<SMomentumd>& Is, const VectorNd& v, VectorNd& result)
{
const unsigned SPATIAL_DIM = 6;
if (Is.size() != v.rows())
throw MissizeException();
// setup the result
result.set_zero(SPATIAL_DIM);
// if the vector is empty, return now
if (Is.empty())
return result;
// verify that all twists are in the same pose
for (unsigned i=1; i< Is.size(); i++)
if (Is[i].pose != Is[i-1].pose)
throw FrameException();
// finally, do the computation
const double* vdata = v.data();
double* rdata = result.data();
for (unsigned j=0; j< SPATIAL_DIM; j++)
for (unsigned i=0; i< Is.size(); i++)
{
const double* Isdata = Is[i].data();
rdata[j] += Isdata[j]*vdata[i];
}
return result;
}
/// Multiplies a vector of spatial momenta by a matrix
MatrixNd& mult(const vector<SMomentumd>& Is, const MatrixNd& m, MatrixNd& result)
{
const unsigned SPATIAL_DIM = 6;
if (Is.size() != m.rows())
throw MissizeException();
// setup the result
result.set_zero(SPATIAL_DIM, m.columns());
// if the vector is empty, return now
if (Is.empty())
return result;
// verify that all twists are in the same pose
for (unsigned i=1; i< Is.size(); i++)
if (Is[i].pose != Is[i-1].pose)
throw FrameException();
// finally, do the computation
double* rdata = result.data();
for (unsigned k=0; k< m.columns(); k++)
{
const double* mdata = m.column(k).data();
for (unsigned j=0; j< SPATIAL_DIM; j++) // j is row index for Is
for (unsigned i=0; i< Is.size(); i++) // i is column index for Is
{
const double* Isdata = Is[i].data();
rdata[k*result.rows()+j] += Isdata[j]*mdata[i];
}
}
return result;
}
/// Multiplies a vector of spatial axes by a vector
SVelocityd mult(const vector<SVelocityd>& t, const VectorNd& v)
{
const unsigned SPATIAL_DIM = 6;
if (t.size() != v.size())
throw MissizeException();
// verify that the vector is not empty - we lose frame info!
if (t.empty())
throw std::runtime_error("loss of frame information");
// setup the result
SVelocityd result = SVelocityd::zero();
// verify that all twists are in the same pose
result.pose = t.front().pose;
for (unsigned i=1; i< t.size(); i++)
if (t[i].pose != result.pose)
throw FrameException();
// finally, do the computation
const double* vdata = v.data();
for (unsigned j=0; j< SPATIAL_DIM; j++)
for (unsigned i=0; i< t.size(); i++)
result[j] += t[i][j]*vdata[i];
return result;
}
/// Sets the quaternion based on the given parameters
QUAT& QUAT::operator=(const VECTORN& v)
{
if (v.size() != 4)
throw MissizeException();
x = v[0];
y = v[1];
z = v[2];
w = v[3];
return *this;
}
