C++ vector::at方法代码示例

    void CPDRigid<T, D>::correspondences()
    {
        _corres.setZero(_M, _N);

        for (size_t n = 0; n < _N; n ++)
        {
            typename std::vector<T> t_exp;
            T sum_exp = 0;
            T c = pow((2*M_PI*_paras._sigma2), 0.5*D) * (_w/(1-_w)) * (T(_M)/_N);
            for (size_t m = 0; m < _M; m ++)
            {
                T m_exp = computeGaussianExp(m, n);
                t_exp.push_back(m_exp);
                sum_exp += m_exp;
            }

            for (size_t m = 0; m < _M; m ++)
            {
                _corres(m, n) = t_exp.at(m) / (sum_exp + c);
            }
        }
    }

    void CPDNRigid<Scalar, Dim>::correspondences()
    {
        this->corres_.setZero(this->M_, this->N_);

        for (size_t n = 0; n < this->N_; n ++)
        {
            typename std::vector<Scalar> t_exp;
            Scalar sum_exp = 0;
            Scalar c = pow((2*M_PI*paras_.sigma2_), 0.5*Dim) * (this->w_/(1-this->w_)) * (Scalar(this->M_)/this->N_);
            for (size_t m = 0; m < this->M_; m ++)
            {
                Scalar m_exp = computeGaussianExp(m, n);
                t_exp.push_back(m_exp);
                sum_exp += m_exp;
            }

            for (size_t m = 0; m < this->M_; m ++)
            {
                this->corres_(m, n) = t_exp.at(m) / (sum_exp + c);
            }
        }
    }

void OrderDownwindForDofDist(SmartPtr<DoFDistribution> dd, ConstSmartPtr<TDomain> domain,
		SmartPtr<UserData<MathVector<TDomain::dim>, TDomain::dim> > spVelocity,
		number time, int si, number threshold)
{
	static const int dim = TDomain::dim;
	const size_t num_ind = dd->num_indices();
	typedef typename std::pair<MathVector<dim>, size_t> pos_type;
	typedef typename std::vector<std::vector<size_t> > adjacency_type;

	//	get positions of indices
	typename std::vector<pos_type> vPositions;
	ExtractPositions(domain, dd, vPositions);

	// get adjacency vector of vectors
	adjacency_type vvConnections;
	dd->get_connections(vvConnections);

	// Check vector sizes match
	if (vvConnections.size() != num_ind)
		UG_THROW("OrderDownstreamForDofDist: "
				"Adjacency list of dimension " << num_ind << " expected, got "<< vvConnections.size());

	if (vPositions.size() != num_ind)
		UG_THROW("OrderDownstreamForDofDist: "
				"Position list of dimension " << num_ind << " expected, got "<< vPositions.size());

	// init helper structures
	std::vector<size_t> vNewIndex(num_ind, 0);
	std::vector<size_t> vAncestorsCount(num_ind, 0);
	std::vector<bool> vVisited(num_ind, false);

	// remove connections that are not in stream direction
	adjacency_type::iterator VertexIter;
	std::vector<size_t>::iterator AdjIter;
	std::vector<size_t> vAdjacency;

	// count how many vertex were kept / removed per adjacency vector
	size_t initialcount, kept, removed = 0;

	MathVector<TDomain::dim> vVel1, vPos1, vPos2, vDir1_2;
	size_t i;
	for (VertexIter = vvConnections.begin(), i=0; VertexIter != vvConnections.end(); VertexIter++, i++)
	{
		UG_DLOG(LIB_DISC_ORDER, 2, "Filtering vertex " << i << " adjacency vector." <<std::endl);
		initialcount = VertexIter->size();
		kept = 0;
		removed = 0;
		// get position and velocity of first trait
		vPos1 = vPositions.at(i).first;
		(*spVelocity)(vVel1, vPos1, time, si);
		if (VecLengthSq(vVel1) == 0 )
		{
			// if the velocity is zero at this trait it does not interfere with others
			// NOTE: otherwise this trait would be downwind-connected to all of it's neighbors
			// NOTE: VertexIter-> will access inner vector functions (*VertexIter) is the inner vector.
			removed = VertexIter->size();
			VertexIter->clear();
		}
		else {
			AdjIter = VertexIter->begin();
			while (AdjIter != VertexIter->end())
			{
				// get position of second trait
				vPos2 = vPositions.at(*AdjIter).first;

				// get difference vector as direction vector
				VecSubtract(vDir1_2, vPos2, vPos1);

				// compute angle between velocity and direction vector
				number anglex1_2 = VecAngle(vDir1_2, vVel1);

				// if angle is smaller then threshold continue else remove connection
				if (anglex1_2 <= threshold && i != *AdjIter)
				{
					vAncestorsCount.at(*AdjIter) += 1;
					++AdjIter;
					kept++;
				} else {
					AdjIter = VertexIter->erase(AdjIter);
					removed++;
				}
			}
		}
		UG_DLOG(LIB_DISC_ORDER, 2, "Kept: " << kept << ", removed: " << removed << " of " << initialcount
				<< " entries in adjacency matrix." << std::endl << std::endl);
	}
	// calculate downwindorder
	// Find vertexes without any ancestors and start NumeriereKnoten on them.
	size_t v,N;
	for (v=0, N=0; v < vvConnections.size(); v++)
	{
		if (vAncestorsCount[v] == 0 && !vVisited[v])
		{
			NumeriereKnoten(vvConnections, vVisited, vAncestorsCount, vNewIndex, N, v);
		}
	}

	// sanity check
	if (N < vvConnections.size()){
		size_t fails = 0;
//.........这里部分代码省略.........

 T get(int v) const
 {
   return m_int2name.at(v);
 }