Ejemplo n.º 1
0
// Kinetic energy integral
double kinetic(int N, Eigen::MatrixXd& A, Eigen::MatrixXd& A_p,
			   Eigen::MatrixXd& A_dp, Eigen::MatrixXd& A_dp_inv,
			   Eigen::MatrixXd& k, Eigen::MatrixXd& k_p,
			   Eigen::MatrixXd& k_dp, double S, Eigen::MatrixXd& L2)
{
	// Calculate the T factor
	// Start with A''^{-1} A' L2 A A''^{-1}
	Eigen::MatrixXd tempMat = A_dp_inv*A_p*L2*A*A_dp_inv;
	
	// Determine k''. A''^{-1} A' L2  A A''^{-1} . k''
	double T = 0.0;
  	for (int i = 0; i < N; i++){
		for (int j = 0; j < N; j++){
			double temp = k_dp(i, 0) * k_dp(j, 0) + k_dp(i, 1) * k_dp(j, 1);
			temp += k_dp(i, 2) * k_dp(j, 2);
			T += tempMat(i, j) * temp;
		}
	}

	// Then k . L2 .  k'
	for (int i = 0; i < N; i++){
		T += k(i, 0) * L2(i, i) *  k_p(i, 0);
		T += k(i, 1) * L2(i, i) * k_p(i, 1);
		T += k(i, 2) * L2(i, i) * k_p(i, 2);
	}

	// And -k'.A L2 A''^{-1}.k''
	tempMat = A*L2*A_dp_inv;
	for (int i = 0; i < N; i++){
		for (int j = 0; j < N; j++){
			double temp = k_p(i, 0) * k_dp(j, 0);
			temp += k_p(i, 1) * k_dp(j, 1) + k_p(i, 2) * k_dp(j, 2);
			T -= tempMat(i, j) * temp;
		}
	}
	
	// And -k''.A''^-1 L2 A'.k
	tempMat = A_dp_inv * L2 *  A_p;
	for (int i = 0; i < N; i++){
		for (int j = 0; j < N; j++){
			double temp = k_dp(i, 0) * k(j, 0);
			temp += k_dp(i, 1) * k(j, 1) + k_dp(i, 2) * k(j, 2);
			T -= tempMat(i, j) * temp;
		}
	}

	
	// This just leaves 6Tr{A A''^-1 A' L2} 
	tempMat = A * A_dp_inv * A_p*L2;
	T += 6.0*tempMat.trace(); 

	T = 0.5*T*S;
	
	return T;
}
Ejemplo n.º 2
0
double weight_unsymkl_gauss(PCObject &o1, PCObject &o2)
{
    int dim = o1.gaussian.dim;
    Eigen::MatrixXd multicov = Eigen::MatrixXd(3,3);
    multicov = o2.gaussian.cov_inverse * o1.gaussian.covariance;
    Eigen::VectorXd mean = o2.gaussian.mean-o1.gaussian.mean;
    double unsymkl_12 = (multicov.trace()
                         + mean.transpose()*o2.gaussian.cov_inverse*mean
                         + log(o1.gaussian.cov_determinant/o2.gaussian.cov_determinant)-dim) / 2.;
//    cout<<"kl: "<<unsymkl_12<<endl;
    return unsymkl_12;
}
Ejemplo n.º 3
0
IGL_INLINE bool igl::copyleft::quadprog(
  const Eigen::MatrixXd & G,  
  const Eigen::VectorXd & g0,  
  const Eigen::MatrixXd & CE, 
  const Eigen::VectorXd & ce0,  
  const Eigen::MatrixXd & CI, 
  const Eigen::VectorXd & ci0, 
  Eigen::VectorXd& x)
{
  using namespace Eigen;
  typedef double Scalar;
  const auto distance = [](Scalar a, Scalar b)->Scalar
  {
  	Scalar a1, b1, t;
  	a1 = std::abs(a);
  	b1 = std::abs(b);
  	if (a1 > b1) 
  	{
  		t = (b1 / a1);
  		return a1 * std::sqrt(1.0 + t * t);
  	}
  	else
  		if (b1 > a1)
  		{
  			t = (a1 / b1);
  			return b1 * std::sqrt(1.0 + t * t);
  		}
  	return a1 * std::sqrt(2.0);
  };
  const auto compute_d = [](VectorXd &d, const MatrixXd& J, const VectorXd& np)
  {
    d = J.adjoint() * np;
  };

  const auto update_z = 
    [](VectorXd& z, const MatrixXd& J, const VectorXd& d,  int iq)
  {
    z = J.rightCols(z.size()-iq) * d.tail(d.size()-iq);
  };

  const auto update_r = 
    [](const MatrixXd& R, VectorXd& r, const VectorXd& d, int iq) 
  {
    r.head(iq) = 
      R.topLeftCorner(iq,iq).triangularView<Upper>().solve(d.head(iq));
  };

  const auto add_constraint = [&distance](
    MatrixXd& R, 
    MatrixXd& J, 
    VectorXd& d, 
    int& iq, 
    double& R_norm)->bool
  {
    int n=J.rows();
#ifdef TRACE_SOLVER
    std::cerr << "Add constraint " << iq << '/';
#endif
    int i, j, k;
    double cc, ss, h, t1, t2, xny;
    
    /* we have to find the Givens rotation which will reduce the element
      d(j) to zero.
      if it is already zero we don't have to do anything, except of
      decreasing j */  
    for (j = n - 1; j >= iq + 1; j--)
    {
      /* The Givens rotation is done with the matrix (cc cs, cs -cc).
        If cc is one, then element (j) of d is zero compared with element
        (j - 1). Hence we don't have to do anything. 
        If cc is zero, then we just have to switch column (j) and column (j - 1) 
        of J. Since we only switch columns in J, we have to be careful how we
        update d depending on the sign of gs.
        Otherwise we have to apply the Givens rotation to these columns.
        The i - 1 element of d has to be updated to h. */
      cc = d(j - 1);
      ss = d(j);
      h = distance(cc, ss);
      if (h == 0.0)
        continue;
      d(j) = 0.0;
      ss = ss / h;
      cc = cc / h;
      if (cc < 0.0)
      {
        cc = -cc;
        ss = -ss;
        d(j - 1) = -h;
      }
      else
        d(j - 1) = h;
      xny = ss / (1.0 + cc);
      for (k = 0; k < n; k++)
      {
        t1 = J(k,j - 1);
        t2 = J(k,j);
        J(k,j - 1) = t1 * cc + t2 * ss;
        J(k,j) = xny * (t1 + J(k,j - 1)) - t2;
      }
    }
    /* update the number of constraints added*/
    iq++;
    /* To update R we have to put the iq components of the d vector
      into column iq - 1 of R
      */
    R.col(iq-1).head(iq) = d.head(iq);
#ifdef TRACE_SOLVER
    std::cerr << iq << std::endl;
#endif
    
    if (std::abs(d(iq - 1)) <= std::numeric_limits<double>::epsilon() * R_norm)
    {
      // problem degenerate
      return false;
    }
    R_norm = std::max<double>(R_norm, std::abs(d(iq - 1)));
    return true;
  };

  const auto delete_constraint = [&distance](
      MatrixXd& R, 
      MatrixXd& J, 
      VectorXi& A, 
      VectorXd& u, 
      int p, 
      int& iq, 
      int l)
  {
    int n = R.rows();
#ifdef TRACE_SOLVER
    std::cerr << "Delete constraint " << l << ' ' << iq;
#endif
    int i, j, k, qq;
    double cc, ss, h, xny, t1, t2;

    /* Find the index qq for active constraint l to be removed */
    for (i = p; i < iq; i++)
      if (A(i) == l)
      {
        qq = i;
        break;
      }

    /* remove the constraint from the active set and the duals */
    for (i = qq; i < iq - 1; i++)
    {
      A(i) = A(i + 1);
      u(i) = u(i + 1);
      R.col(i) = R.col(i+1);
    }

    A(iq - 1) = A(iq);
    u(iq - 1) = u(iq);
    A(iq) = 0; 
    u(iq) = 0.0;
    for (j = 0; j < iq; j++)
      R(j,iq - 1) = 0.0;
    /* constraint has been fully removed */
    iq--;
#ifdef TRACE_SOLVER
    std::cerr << '/' << iq << std::endl;
#endif 

    if (iq == 0)
      return;

    for (j = qq; j < iq; j++)
    {
      cc = R(j,j);
      ss = R(j + 1,j);
      h = distance(cc, ss);
      if (h == 0.0)
        continue;
      cc = cc / h;
      ss = ss / h;
      R(j + 1,j) = 0.0;
      if (cc < 0.0)
      {
        R(j,j) = -h;
        cc = -cc;
        ss = -ss;
      }
      else
        R(j,j) = h;

      xny = ss / (1.0 + cc);
      for (k = j + 1; k < iq; k++)
      {
        t1 = R(j,k);
        t2 = R(j + 1,k);
        R(j,k) = t1 * cc + t2 * ss;
        R(j + 1,k) = xny * (t1 + R(j,k)) - t2;
      }
      for (k = 0; k < n; k++)
      {
        t1 = J(k,j);
        t2 = J(k,j + 1);
        J(k,j) = t1 * cc + t2 * ss;
        J(k,j + 1) = xny * (J(k,j) + t1) - t2;
      }
    }
  };

  int i, j, k, l; /* indices */
  int ip, me, mi;
  int n=g0.size();  int p=ce0.size();  int m=ci0.size();  
  MatrixXd R(G.rows(),G.cols()), J(G.rows(),G.cols());
  
  LLT<MatrixXd,Lower> chol(G.cols());
 
  VectorXd s(m+p), z(n), r(m + p), d(n),  np(n), u(m + p);
  VectorXd x_old(n), u_old(m + p);
  double f_value, psi, c1, c2, sum, ss, R_norm;
  const double inf = std::numeric_limits<double>::infinity();
  double t, t1, t2; /* t is the step length, which is the minimum of the partial step length t1 
    * and the full step length t2 */
  VectorXi A(m + p), A_old(m + p), iai(m + p);
  int q;
  int iq, iter = 0;
  std::vector<bool> iaexcl(m + p);
 	
  me = p; /* number of equality constraints */
  mi = m; /* number of inequality constraints */
  q = 0;  /* size of the active set A (containing the indices of the active constraints) */
  
  /*
   * Preprocessing phase
   */
	
  /* compute the trace of the original matrix G */
  c1 = G.trace();
	
	/* decompose the matrix G in the form LL^T */
  chol.compute(G);
 
  /* initialize the matrix R */
  d.setZero();
  R.setZero();
	R_norm = 1.0; /* this variable will hold the norm of the matrix R */
  
	/* compute the inverse of the factorized matrix G^-1, this is the initial value for H */
  // J = L^-T
  J.setIdentity();
  J = chol.matrixU().solve(J);
	c2 = J.trace();
#ifdef TRACE_SOLVER
 print_matrix("J", J, n);
#endif
  
	/* c1 * c2 is an estimate for cond(G) */
  
	/* 
   * Find the unconstrained minimizer of the quadratic form 0.5 * x G x + g0 x 
   * this is a feasible point in the dual space
	 * x = G^-1 * g0
   */
  x = chol.solve(g0);
  x = -x;
	/* and compute the current solution value */ 
	f_value = 0.5 * g0.dot(x);
#ifdef TRACE_SOLVER
  std::cerr << "Unconstrained solution: " << f_value << std::endl;
  print_vector("x", x, n);
#endif
  
	/* Add equality constraints to the working set A */
  iq = 0;
	for (i = 0; i < me; i++)
	{
    np = CE.col(i);
    compute_d(d, J, np);
		update_z(z, J, d,  iq);
		update_r(R, r, d,  iq);
#ifdef TRACE_SOLVER
		print_matrix("R", R, iq);
		print_vector("z", z, n);
		print_vector("r", r, iq);
		print_vector("d", d, n);
#endif
    
    /* compute full step length t2: i.e., the minimum step in primal space s.t. the contraint 
      becomes feasible */
    t2 = 0.0;
    if (std::abs(z.dot(z)) > std::numeric_limits<double>::epsilon()) // i.e. z != 0
      t2 = (-np.dot(x) - ce0(i)) / z.dot(np);
    
    x += t2 * z;

    /* set u = u+ */
    u(iq) = t2;
    u.head(iq) -= t2 * r.head(iq);
    
    /* compute the new solution value */
    f_value += 0.5 * (t2 * t2) * z.dot(np);
    A(i) = -i - 1;
    
    if (!add_constraint(R, J, d, iq, R_norm))
    {
      // FIXME: it should raise an error
      // Equality constraints are linearly dependent
      return false;
    }
  }
  
	/* set iai = K \ A */
	for (i = 0; i < mi; i++)
		iai(i) = i;
  
l1:	iter++;
#ifdef TRACE_SOLVER
  print_vector("x", x, n);
#endif
  /* step 1: choose a violated constraint */
	for (i = me; i < iq; i++)
	{
	  ip = A(i);
		iai(ip) = -1;
	}
	
	/* compute s(x) = ci^T * x + ci0 for all elements of K \ A */
	ss = 0.0;
	psi = 0.0; /* this value will contain the sum of all infeasibilities */
	ip = 0; /* ip will be the index of the chosen violated constraint */
	for (i = 0; i < mi; i++)
	{
		iaexcl[i] = true;
		sum = CI.col(i).dot(x) + ci0(i);
		s(i) = sum;
		psi += std::min(0.0, sum);
	}
#ifdef TRACE_SOLVER
  print_vector("s", s, mi);
#endif

    
	if (std::abs(psi) <= mi * std::numeric_limits<double>::epsilon() * c1 * c2* 100.0)
	{
    /* numerically there are not infeasibilities anymore */
    q = iq;
		return true;
  }
    
  /* save old values for u, x and A */
   u_old.head(iq) = u.head(iq);
   A_old.head(iq) = A.head(iq);
   x_old = x;
    
l2: /* Step 2: check for feasibility and determine a new S-pair */
	for (i = 0; i < mi; i++)
	{
		if (s(i) < ss && iai(i) != -1 && iaexcl[i])
		{
			ss = s(i);
			ip = i;
		}
	}
  if (ss >= 0.0)
  {
    q = iq;
    return true;
  }
    
  /* set np = n(ip) */
  np = CI.col(ip);
  /* set u = (u 0)^T */
  u(iq) = 0.0;
  /* add ip to the active set A */
  A(iq) = ip;

#ifdef TRACE_SOLVER
	std::cerr << "Trying with constraint " << ip << std::endl;
	print_vector("np", np, n);
#endif
    
l2a:/* Step 2a: determine step direction */
  /* compute z = H np: the step direction in the primal space (through J, see the paper) */
  compute_d(d, J, np);
  update_z(z, J, d, iq);
  /* compute N* np (if q > 0): the negative of the step direction in the dual space */
  update_r(R, r, d, iq);
#ifdef TRACE_SOLVER
  std::cerr << "Step direction z" << std::endl;
		print_vector("z", z, n);
		print_vector("r", r, iq + 1);
    print_vector("u", u, iq + 1);
    print_vector("d", d, n);
    print_ivector("A", A, iq + 1);
#endif
    
  /* Step 2b: compute step length */
  l = 0;
  /* Compute t1: partial step length (maximum step in dual space without violating dual feasibility */
  t1 = inf; /* +inf */
  /* find the index l s.t. it reaches the minimum of u+(x) / r */
  for (k = me; k < iq; k++)
  {
    double tmp;
    if (r(k) > 0.0 && ((tmp = u(k) / r(k)) < t1) )
    {
      t1 = tmp;
      l = A(k);
    }
  }
  /* Compute t2: full step length (minimum step in primal space such that the constraint ip becomes feasible */
  if (std::abs(z.dot(z))  > std::numeric_limits<double>::epsilon()) // i.e. z != 0
    t2 = -s(ip) / z.dot(np);
  else
    t2 = inf; /* +inf */

  /* the step is chosen as the minimum of t1 and t2 */
  t = std::min(t1, t2);
#ifdef TRACE_SOLVER
  std::cerr << "Step sizes: " << t << " (t1 = " << t1 << ", t2 = " << t2 << ") ";
#endif
  
  /* Step 2c: determine new S-pair and take step: */
  
  /* case (i): no step in primal or dual space */
  if (t >= inf)
  {
    /* QPP is infeasible */
    // FIXME: unbounded to raise
    q = iq;
    return false;
  }
  /* case (ii): step in dual space */
  if (t2 >= inf)
  {
    /* set u = u +  t * [-r 1) and drop constraint l from the active set A */
    u.head(iq) -= t * r.head(iq);
    u(iq) += t;
    iai(l) = l;
    delete_constraint(R, J, A, u, p, iq, l);
#ifdef TRACE_SOLVER
    std::cerr << " in dual space: " 
      << f_value << std::endl;
    print_vector("x", x, n);
    print_vector("z", z, n);
		print_ivector("A", A, iq + 1);
#endif
    goto l2a;
  }
  
  /* case (iii): step in primal and dual space */
  
  x += t * z;
  /* update the solution value */
  f_value += t * z.dot(np) * (0.5 * t + u(iq));
  
  u.head(iq) -= t * r.head(iq);
  u(iq) += t;
#ifdef TRACE_SOLVER
  std::cerr << " in both spaces: " 
    << f_value << std::endl;
	print_vector("x", x, n);
	print_vector("u", u, iq + 1);
	print_vector("r", r, iq + 1);
	print_ivector("A", A, iq + 1);
#endif
  
  if (t == t2)
  {
#ifdef TRACE_SOLVER
    std::cerr << "Full step has taken " << t << std::endl;
    print_vector("x", x, n);
#endif
    /* full step has taken */
    /* add constraint ip to the active set*/
		if (!add_constraint(R, J, d, iq, R_norm))
		{
			iaexcl[ip] = false;
			delete_constraint(R, J, A, u, p, iq, ip);
#ifdef TRACE_SOLVER
      print_matrix("R", R, n);
      print_ivector("A", A, iq);
#endif
			for (i = 0; i < m; i++)
				iai(i) = i;
			for (i = 0; i < iq; i++)
			{
				A(i) = A_old(i);
				iai(A(i)) = -1;
				u(i) = u_old(i);
			}
			x = x_old;
      goto l2; /* go to step 2 */
		}    
    else
      iai(ip) = -1;
#ifdef TRACE_SOLVER
    print_matrix("R", R, n);
    print_ivector("A", A, iq);
#endif
    goto l1;
  }
  
  /* a patial step has taken */
#ifdef TRACE_SOLVER
  std::cerr << "Partial step has taken " << t << std::endl;
  print_vector("x", x, n);
#endif
  /* drop constraint l */
	iai(l) = l;
	delete_constraint(R, J, A, u, p, iq, l);
#ifdef TRACE_SOLVER
  print_matrix("R", R, n);
  print_ivector("A", A, iq);
#endif
  
  s(ip) = CI.col(ip).dot(x) + ci0(ip);

#ifdef TRACE_SOLVER
  print_vector("s", s, mi);
#endif
  goto l2a;
}