void CosineTreeBuilder::CTNode(arma::mat A, CosineTree& root)
{
  A = A.t();
  Log::Info<<"CTNode"<<std::endl;
  //Calculating Centroid
  arma::rowvec centroid = CalculateCentroid(A);
  //Calculating sampling probabilities
  arma::vec probabilities = arma::zeros<arma::vec>(A.n_rows,1);
  LSSampling(A,probabilities);
  //Setting Values
  root.Probabilities(probabilities);
  root.Data(A);
  root.Centroid(centroid);
}
// [[Rcpp::export]]
arma::vec innerLoop(arma::vec resp,
                    arma::vec beta, double intercept,
                    double tol, int max_iter,
                    arma::mat x_mat,
                    int n, arma::vec weights) {
  bool converge = false;
  int counter = 0;

  arma::vec temp_resp;
  arma::vec beta_new = beta;
  double intercept_new;

  while(!converge && counter < max_iter) {

    temp_resp = x_mat.t() * ((resp - intercept) / n);

    // The argmin is hence equivalent to that of
    // (1/2) * ||v - beta||_2^2 + 4 * lam * Pen(beta).
    // In main func weights will be weights.col(i)

    beta_new = GetProxOne(temp_resp, 4 * weights);
    intercept_new =  mean(resp - x_mat * beta_new);


    double change1 = pow(intercept_new - intercept, 2) + sum(square(beta_new - beta));
    double change2 = pow(intercept_new, 2) + sum(square(beta_new));;


    if( pow(change1, 0.5) / pow(change2, 0.5) < tol ) {
      beta = beta_new;
      intercept = intercept_new;
      converge = true;
    } else {
      beta = beta_new;
      intercept  = intercept_new;
      counter = counter + 1;
      if(counter == max_iter) {
        beta = beta_new;
        intercept = intercept_new;
        Function warning("warning");
        warning("Function did not converge for inner loop for some lambda.");
      }
    }

  }
  arma::vec inter_vec(1);
  inter_vec(0) = intercept;
  return join_vert(inter_vec, beta);

}
Exemple #3
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// [[Rcpp::export]]
arma::mat expskewC(arma::mat M){
  /*This function takes a 3-by-3 skew symmetric matrix (in so(3)) and
  returns the exponential, a 3-by-3 rotations (in SO(3))*/
  
  double MMt = sum(sum(M-M.t()));
  
  if(fabs(MMt)>0.01){
    throw Rcpp::exception("The exp.skew function is expecting a 3-by-3 skew symmetric matrix");
  }
  
  arma::mat expM(3,3);
  expM.eye();
  
  double a = pow(0.5*trace(M.t()*M),0.5);
  
  if(a < 0.000001 && a > -0.000001){
    return expM;
  }
   
  expM = expM + (sin(a)/a) * M + (1-cos(a))*pow(a,-2)*M*M;
  
  return expM;
  
}
//evaluate Hessian operator on Z
//eucH is the ordinary Hessian matrix on Z in the ambient space
//return <Z, Hessian*Z>_Y
double specialLinear::evalHessian(const arma::mat & eucH,const arma::mat & Z){
  arma::mat YU,eucH_proj,Weingarten,Weingarten_part,temp;
  //project euclidian Hessian onto tangent space
  YU=eucH*Y.i();
  YU=1.0/n*(arma::trace(YU))*Y;
  eucH_proj=eucH-YU;
  //Weingarten Map
  Weingarten=-1.0/n*(arma::dot(eucH.t(),Y.i()))*Z;
  Weingarten_part=1.0/n*eucH*Y.i()*Z;
  temp=1.0/n*(arma::dot(Weingarten_part.t(),Y.i()))*Y;
  Weingarten_part-=temp;
  Weingarten+=Weingarten_part;
  hessian_Z=eucH_proj+Weingarten;
  Z_hessian_Z=arma::dot(hessian_Z,Z);
  return Z_hessian_Z;
}
arma::vec cpp_UpdateGamma (arma::mat x_big, arma::vec weights_big,
                           arma::vec y_big, 
                           arma::vec gamma, arma::vec beta, 
                           double lambda) {
  // Another helper function used by the main algorithm.
  // In this algorithm we loop through and do a coordinate wise update of
  // gamma.
  // 
  // Agrs: 
  //    beta/gamma: The 'current' parameter vectors.
  //    x/weights/y_big: Design, weights and response for the big population.
  //    lambda: The value of the penalty parameter.
  // Returns:
  //    gamma: The updated gamma vector. 
  

  // Obtain value of dimension.
  int p = gamma.size();
  
  // Initialize matrix X * beta. 
  arma::mat x_beta = x_big * beta;
  
  // We need the diagonal entries of X^T * W * X.
  // This is easy when W is a diagonal matrix.
  arma::mat W_times_X(x_big.begin(), x_big.n_rows, x_big.n_cols, true);
  W_times_X.each_col() %= weights_big;
  // We obtain the diagonal entries of X^T * W * X for the denominators.
  arma::mat Xt_W_X = x_big.t() * W_times_X;
  arma::vec denoms = Xt_W_X.diag();
  
  // Some temporary vectors which we use later.
  arma::vec temp_gamma(gamma.begin(), gamma.size(), true);
  double temp1;
  
  // Loop through the different gamma values which need to be updated.
  for(int i = 0; i < p; i++) {
    // Instead of excluding a column we simply set gamma_j = 0 to get the fitted
    // value without the effect of gamma_j.
    temp_gamma(i) = 0;
    temp1 = as_scalar(x_big.col(i).t() * (weights_big % (y_big - x_beta - x_big * temp_gamma)));
    gamma(i) = (cpp_sign(temp1) * cpp_max(abs(temp1) - lambda, 0.0))/denoms(i);
    
    temp_gamma(i) = gamma(i);
    
  }
  return gamma;
}
Exemple #6
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// [[Rcpp::export]]
arma::mat logSO3C(arma::mat R){
  
  arma::mat I(3,3), logR(3,3);
  I.eye();
  
  double theta = acos(0.5*trace(R)-0.5);
  
  if(theta < 0.0001){
    logR.zeros();
    return logR;
  }
  
  logR = (R-R.t())*theta/(2*sin(theta));
  
  return logR;
  
}
Exemple #7
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// Uses singular value decomposition function svd() from Armadillo.
// Thus, be sure to define the following in /path/to/armadillo/include/armadillo_bits/config.hpp:
// ARMA_USE_LAPACK
// ARMA_USE_BLAS
// ARMA_BLAS_UNDERSCORE
int PCA::Run(const DataUnlabeledNormalized &data_unlabeled_normalized) {
  const int kNumTrainEx = data_unlabeled_normalized.num_train_ex();
  assert(kNumTrainEx >= 1);
  const arma::mat kTrainingFeatures = \
    data_unlabeled_normalized.training_features_normalized();
  const arma::mat kCovMat = \
    (1.0/(float)kNumTrainEx)*kTrainingFeatures.t()*kTrainingFeatures;
  const int kNumRows = kCovMat.n_rows;
  arma::mat left_sing_vec = arma::zeros<arma::mat>(kNumRows,kNumRows);
  arma::vec sing_val = arma::zeros<arma::vec>(kNumRows,1);
  arma::mat right_sing_vec = arma::zeros<arma::mat>(kNumRows,kNumRows);
  arma::svd(left_sing_vec,sing_val,right_sing_vec,kCovMat);
  this->set_left_sing_vec(left_sing_vec);
  this->set_sing_val(sing_val);

  return 0;
}
Exemple #8
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// // [[Rcpp::export()]]
arma::mat getEx2x2_ordIRT(const arma::mat &Ex,
                   const arma::mat &Vx,
                   const int N) {

    arma::mat Ex2x2(2, 2, arma::fill::zeros) ;
    arma::mat tmp(1, 1) ;
    tmp.fill(N) ;

    arma::mat S = tmp % Vx + Ex.t() * Ex ;

    Ex2x2(0, 0) = N ;
    Ex2x2(1, 1) = S(0,0) ;

    arma::mat sums = sum(Ex, 0) ;
    Ex2x2(1, 0) = sums(0,0) ;
    Ex2x2(0, 1) = sums(0,0) ;

    return(Ex2x2) ;

}
Exemple #9
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double
HMM::forwardProcedureCached() {

  //initialisation
  alpha_.col(0) = arma::trans(pi_ % B_.row(0));

  c_(0) = arma::accu(alpha_.col(0));
  alpha_.col(0) /= arma::as_scalar(c_(0));

  //alpha_.print("alpha");
  //c_.print("scale");
  //iteration
  for(unsigned int t = 1; t < T_; ++t) {
    alpha_.col(t) = (A_.t() * alpha_.col(t-1)) % arma::trans(B_.row(t));
    c_(t) = arma::accu(alpha_.col(t));
    alpha_.col(t) /= arma::as_scalar(c_(t)); 
  }

  pprob_ = arma::accu(arma::log(c_));
  return pprob_;
}
Exemple #10
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// [[Rcpp::export]]   
arma::rowvec meanQ4C(arma::mat Q) { 
	//Compute the projected mean of the sample Q
	
	NumericMatrix Qss = as<NumericMatrix>(wrap(Q));
	int cq4 = checkQ4(Qss);
	if(cq4){
		throw Rcpp::exception("The data are not in Q4.");
	}
	
	arma::mat Qsq=Q.t()*Q;
	arma::mat eigvec;
	arma::vec eigval;
  arma::eig_sym(eigval,eigvec,Qsq);   
  arma::vec qhat=eigvec.col(3);
  
  if(qhat[0]<0){
  	qhat = -qhat;
  }
  
  return qhat.t(); //Want to return it in a row vector so transpose it
}
Exemple #11
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/**
 * Compute
 *
 *     alpha = min(1, tau * alphahat(A, dA))
 *
 * where
 *
 *     alphahat = sup{ alphahat : A + dA is psd }
 *
 * See (2.18) of [AHO98] for more details.
 */
static inline double
Alpha(const arma::mat& A, const arma::mat& dA, double tau)
{
  // On Armadillo < 4.500, the "lower" option isn't available.
#if (ARMA_VERSION_MAJOR < 4) || \
    ((ARMA_VERSION_MAJOR == 4) && (ARMA_VERSION_MINOR < 500))
  const arma::mat L = arma::chol(A).t(); // This is less efficient.
#else
  const arma::mat L = arma::chol(A, "lower");
#endif
  const arma::mat Linv = arma::inv(arma::trimatl(L));
  // TODO(stephentu): We only want the top eigenvalue, we should
  // be able to do better than full eigen-decomposition.
  const arma::vec evals = arma::eig_sym(-Linv * dA * Linv.t());
  const double alphahatinv = evals(evals.n_elem - 1);
  double alphahat = 1. / alphahatinv;
  if (alphahat < 0.)
    // dA is PSD already
    alphahat = 1.;
  return std::min(1., tau * alphahat);
}
Exemple #12
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// [[Rcpp::export]]
arma::rowvec HnCpp(arma::mat Qs){
  //Compute the Hn tests statistics
  
  int n = Qs.n_rows, i=0;
  arma::mat T = Qs.t()*Qs;
  arma::mat eigvec, eigvecJ;
  arma::vec eigval, eigvalJ;
  arma::eig_sym(eigval,eigvec,T);
  arma::rowvec Hn(n);
  arma::rowvec Qj;
  arma::mat Tj;

  for(i = 0;i<n; i++){
    Qj = Qs.row(i);
    
    Tj = T-Qj.t()*Qj;
    arma::eig_sym(eigvalJ,eigvecJ,Tj);
    Hn(i)=(n-2)*(1+eigvalJ(3)-eigval(3))/(n-1-eigvalJ(3));
    
  }
  return Hn;
}
Exemple #13
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NumericVector logLikMixHMM(const arma::mat& transition, const arma::cube& emission,
  const arma::vec& init, const arma::ucube& obs, const arma::mat& coef, const arma::mat& X,
  const arma::uvec& numberOfStates, unsigned int threads) {
  
  arma::mat weights = exp(X * coef).t();
  if (!weights.is_finite()) {
    return wrap(-arma::datum::inf);
  }
  weights.each_row() /= sum(weights, 0);
  
  arma::vec ll(obs.n_slices);
  arma::sp_mat transition_t(transition.t());
#pragma omp parallel for if(obs.n_slices >= threads) schedule(static) num_threads(threads) \
  default(none) shared(ll, obs, weights, init, emission, transition_t, numberOfStates)
    for (unsigned int k = 0; k < obs.n_slices; k++) {
      arma::vec alpha = init % reparma(weights.col(k), numberOfStates);
      
      for (unsigned int r = 0; r < obs.n_rows; r++) {
        alpha %= emission.slice(r).col(obs(r, 0, k));
      }
      
      double tmp = sum(alpha);
      ll(k) = log(tmp);
      alpha /= tmp;
      
      for (unsigned int t = 1; t < obs.n_cols; t++) {
        alpha = transition_t * alpha;
        for (unsigned int r = 0; r < obs.n_rows; r++) {
          alpha %= emission.slice(r).col(obs(r, t, k));
        }
        
        tmp = sum(alpha);
        ll(k) += log(tmp);
        alpha /= tmp;
      }
    }
    return wrap(ll);
}
Exemple #14
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QUIC_SVD::QUIC_SVD(const arma::mat& dataset,
                   arma::mat& u,
                   arma::mat& v,
                   arma::mat& sigma,
                   const double epsilon,
                   const double delta) :
    dataset(dataset)
{
  // Since columns are sample in the implementation, the matrix is transposed if
  // necessary for maximum speedup.
  CosineTree* ctree;
  if (dataset.n_cols > dataset.n_rows)
    ctree = new CosineTree(dataset, epsilon, delta);
  else
    ctree = new CosineTree(dataset.t(), epsilon, delta);

  // Get subspace basis by creating the cosine tree.
  ctree->GetFinalBasis(basis);

  // Use the ExtractSVD algorithm mentioned in the paper to extract the SVD of
  // the original dataset in the obtained subspace.
  ExtractSVD(u, v, sigma);
}
Exemple #15
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// // [[Rcpp::export()]]
arma::mat getEx2x2(const arma::mat &Ex,
                   const arma::mat &Vx,
                   const int N,
                   const int D
                   ) {
    arma::mat Ex2x2(D + 1, D + 1, arma::fill::zeros) ;
    arma::mat tmp(D, D) ;
    tmp.fill(N) ;
    arma::mat S = tmp % Vx + Ex.t() * Ex ;

    // S.print("S") ;
    // (tmp % Vx).print("tmp") ;

    Ex2x2(0, 0) = N ;
    Ex2x2.submat(1, 1, D, D) = S ;

    arma::mat sums = sum(Ex, 0) ;
    for (int d = 0; d < D ; d++) {
        Ex2x2(d + 1, 0) = sums(0,d) ;
        Ex2x2(0, d + 1) = sums(0,d) ;
    }
    return(Ex2x2) ;
}
Exemple #16
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// [[Rcpp::depends(RcppArmadillo)]]
// [[Rcpp::export]]
arma::mat FFBS(int t_T, double a2, arma::vec delta, arma::vec m0, arma::mat C0, Rcpp::List FF, arma::mat GG, Rcpp::List Eta_k) {
    int p = C0.n_rows;
    //create vectors for m, a
    arma::mat Alpha_k(p,t_T);
    arma::mat m(p,t_T);
    arma::mat a(p,t_T);

    Rcpp::List C;
    Rcpp::List R_inv;

    double a2_inv = (1.0/a2);

    for(int t = 0; t<t_T; t++) {

        arma::mat F_t = FF[t];
        arma::vec Eta_kt = Eta_k[t];
        arma::mat P_star(p,p);

        if(t == 0 ) {
            a.col(t) = GG*m0;
            P_star = GG*C0*GG.t();
        } else {
            arma::mat C_tm1 = C[t - 1];
            a.col(t) = GG*m.col(t - 1);
            P_star = GG*C_tm1*GG.t();
        }

        //Rcpp::Rcout << "C_{t-1}: " << P_star << std::endl;
        arma::mat P_inv = P_star.i();
        arma::vec f_t = F_t * a.col(t);
        arma::mat R_t = P_star;    //if i were to think about not discounting it would be here  R_t = P_t + W_t
        R_t.diag() = R_t.diag() + delta;
        arma::mat R_t_inv = R_t.i();
        R_inv.push_back( R_t_inv );      // and here.  W_t = diag( (1-delta)/delta C_{t-1}[1,1], .00001)

        //Rcpp::Rcout << "R_t: " << R_t << std::endl;

        arma::mat Q_t = F_t * R_t * F_t.t();
        Q_t.diag() = Q_t.diag() + a2;

        //Woodbury Sherman Matrix Inversion
        arma::mat Q_inv_t = - a2_inv * F_t * arma::inv(R_t_inv + a2_inv * F_t.t() * F_t ) * a2_inv * F_t.t();
        Q_inv_t.diag() = Q_inv_t.diag() + a2_inv;

        arma::mat A_t = R_t * F_t.t() * Q_inv_t;
        //Rcpp::Rcout << "A_t: " << A_t << std::endl;
        //Rcpp::Rcout << "R_t: " << R_t << std::endl;
        arma::mat C_t = R_t - A_t * Q_t * A_t.t();
        C.push_back(C_t);

        m.col(t) = a.col(t) + A_t * (Eta_kt - f_t );
    }

    //now do backward sampling

    for(int t = (t_T - 1); t>=0; t--) {
        arma::mat C_t = C[t];

        if(t == (t_T - 1) ) {
            Alpha_k.col(t) = m.col(t) + arma::trans( arma::randn(1,p) * arma::chol(C_t) );
        } else {
            arma::mat R_inv_tp1 = R_inv[t + 1];
            arma::vec b = m.col(t) + C_t*GG.t()* R_inv_tp1 * (Alpha_k.col(t + 1) - a.col( t + 1) );
            arma::mat B = C_t - C_t*GG.t()*R_inv_tp1*GG*C_t;
            Alpha_k.col(t) = b + arma::trans( arma::randn(1,p) * arma::chol(B) );
        }
    }//end of backward sampling

    return Alpha_k;
}
Exemple #17
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// **********************************************************//
//                  Transpose                                //
// **********************************************************//
// [[Rcpp::export]]
arma::mat transpose (arma::mat x) {
	return x.t();
}
Exemple #18
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void RandomizedSVD::Apply(const arma::mat& data,
                          arma::mat& u,
                          arma::vec& s,
                          arma::mat& v,
                          const size_t rank)
{
  if (iteratedPower == 0)
    iteratedPower = rank + 2;

  // Center the data into a temporary matrix.
  arma::vec rowMean = arma::sum(data, 1) / data.n_cols;

  arma::mat R, Q, Qdata;
  ann::RandomInitialization randomInit;

  // Apply the centered data matrix to a random matrix, obtaining Q.
  if (data.n_cols >= data.n_rows)
  {
    randomInit.Initialize(R, data.n_rows, iteratedPower);
    Q = (data.t() * R) - arma::repmat(arma::trans(R.t() * rowMean),
        data.n_cols, 1);
  }
  else
  {
    randomInit.Initialize(R, data.n_cols, iteratedPower);
    Q = (data * R) - (rowMean * (arma::ones(1, data.n_cols) * R));
  }

  // Form a matrix Q whose columns constitute a
  // well-conditioned basis for the columns of the earlier Q.
  if (maxIterations == 0)
  {
    arma::qr_econ(Q, v, Q);
  }
  else
  {
    arma::lu(Q, v, Q);
  }

  // Perform normalized power iterations.
  for (size_t i = 0; i < maxIterations; ++i)
  {
    if (data.n_cols >= data.n_rows)
    {
      Q = (data * Q) - rowMean * (arma::ones(1, data.n_cols) * Q);
      arma::lu(Q, v, Q);
      Q = (data.t() * Q) - arma::repmat(rowMean.t() * Q, data.n_cols, 1);
    }
    else
    {
      Q = (data.t() * Q) - arma::repmat(rowMean.t() * Q, data.n_cols, 1);
      arma::lu(Q, v, Q);
      Q = (data * Q) - (rowMean * (arma::ones(1, data.n_cols) * Q));
    }

    // Computing the LU decomposition is more efficient than computing the QR
    // decomposition, so we only use in the last iteration, a pivoted QR
    // decomposition which renormalizes Q, ensuring that the columns of Q are
    // orthonormal.
    if (i < (maxIterations - 1))
    {
      arma::lu(Q, v, Q);
    }
    else
    {
      arma::qr_econ(Q, v, Q);
    }
  }

  // Do economical singular value decomposition and compute only the
  // approximations of the left singular vectors by using the centered data
  // applied to Q.
  if (data.n_cols >= data.n_rows)
  {
    Qdata = (data * Q) - rowMean * (arma::ones(1, data.n_cols) * Q);
    arma::svd_econ(u, s, v, Qdata);
    v = Q * v;
  }
  else
  {
    Qdata = (Q.t() * data) - arma::repmat(Q.t() * rowMean, 1,  data.n_cols);
    arma::svd_econ(u, s, v, Qdata);
    u = Q * u;
  }
}
Exemple #19
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/* Set and get methods for the Kalman filter */
void kalmanFilter::setTransistion(arma::mat T) {
	transistionMatrix = T;
	transistionMatrixT = T.t();
}
int main()
{
  // LOAD DATA
  arma::mat X;

  // A) Toy Data
  //  char inputFile[] = "../data_files/toyclusters/toyclusters.dat";
  
  // B) X4.dat
  //char inputFile[] = "./X4.dat";
  
  // C) fisher data
  //char inputFile[] = "./fisher.dat";

  // D) MNIST data
  //char inputFile[] = "../data_files/MNIST/MNIST.dat";
  
  // E) Reduced MNIST (5000x400)
  //char inputFile[] = "../data_files/MNIST/MNISTreduced.dat";
  
  // F) Reduced MNIST (0 and 1) (1000x400)
  //char inputFile[] = "../data_files/MNIST/MNISTlittle.dat";

  // G) Girl.png (512x768, RGB, already unrolled)
  //char inputFile[] = "girl.dat";

  // H) Pool.png (383x512, RGB, already unrolled)
  //char inputFile[] = "pool.dat";

  // I) Cat.png (733x490, RGB, unrolled)
  //char inputFile[] = "cat.dat";
  
  // J) Airplane.png (512x512, RGB, unrolled)
  //char inputFile[] = "airplane.dat";

  // K) Monarch.png (512x768, RGB, unrolled)
  //char inputFile[] = "monarch.dat";

  // L) tulips.png (512x768 ,RGB, unrolled)
  //char inputFile[] = "tulips.dat";
  
  // M) demo.dat (2d data)
  char inputFile[] = "demo.dat";

  // INITIALIZE PARAMETERS
  X.load(inputFile);
  const arma::uword N = X.n_rows;
  const arma::uword D = X.n_cols;

  arma::umat ids(N,1);	// needed to shuffle indices later
  arma::umat shuffled_ids(N,1);
  for (arma::uword i = 0; i < N; ++i) {
    ids(i,0) = i;
  }
  
  arma::arma_rng::set_seed_random(); // set arma rng
  // int seed = time(NULL);	// set RNG seed to current time
  // srand(seed);

  arma::uword initial_K = 32;   // initial number of clusters
  arma::uword K = initial_K;
  
  arma::umat clusters(N,1); // contains cluster assignments for each data point
  for (arma::uword i = 0; i < N; ++i) {
    clusters(i, 0) = i%K;		// initialize as [0,1,...,K-1,0,1,...,K-1,0,...]
  }

  arma::umat cluster_sizes(N,1,arma::fill::zeros); // contains num data points in cluster k
  for (arma::uword i = 0; i < N; ++i) {
    cluster_sizes(clusters(i,0), 0) += 1;
  }

  arma::mat mu(N, D, arma::fill::zeros); // contains cluster mean parameters
  arma::mat filler(D,D,arma::fill::eye);
  std::vector<arma::mat> sigma(N,filler); // contains cluster covariance parameters

  if (K < N) {			// set parameters not belonging to any cluster to -999
    mu.rows(K,N-1).fill(-999);
    for (arma::uword k = K; k < N; ++k) {
      sigma[k].fill(-999);
    }
  }

  arma::umat uword_dummy(1,1);	// dummy 1x1 matrix;
  // for (arma::uword i = 0; i <N; ++i) {
  //   std::cout << sigma[i] << std::endl;
  // }
  // std::cout << X << std::endl
  // 	    << N << std::endl
  // 	    << D << std::endl
  // 	    << K << std::endl
  // 	    << clusters << std::endl
  // 	    << cluster_sizes << std::endl
  //	    << ids << std::endl;

  // INITIALIZE HYPER PARAMETERS
  // Dirichlet Process concentration parameter is alpha:
  double alpha = 1;
  // Dirichlet Process base distribution (i.e. prior) is 
  // H(mu,sigma) = NIW(mu,Sigma|m_0,k_0,S_0,nu_0) = N(mu|m_0,Sigma/k_0)IW(Sigma|S_0,nu_0)
  arma::mat perturbation(D,D,arma::fill::eye);
  perturbation *= 0.000001;
  //const arma::mat S_0 = arma::cov(X,X,1) + perturbation; // S_xbar / N
  const arma::mat S_0(D,D,arma::fill::eye);
  const double nu_0 = D + 2;
  const arma::mat m_0 = mean(X).t();
  const double k_0 = 0.01;
  // std::cout << "S_0" << S_0 << std::endl;
  // std::cout << S_0 << std::endl
  // 	    << nu_0 << std::endl
  // 	    << m_0 << std::endl
  // 	    << k_0 << std::endl;


  // INITIALIZE SAMPLING PARAMETERS
  arma::uword NUM_SWEEPS = 250;	// number of Gibbs iterations
  bool SAVE_CHAIN = false;	// save output of each Gibbs iteration?
  // arma::uword BURN_IN = NUM_SWEEPS - 10;
  // arma::uword CHAINSIZE = NUM_SWEEPS - BURN_IN;
  // std::vector<arma::uword> chain_K(CHAINSIZE, K); // Initialize chain variable to initial parameters for convinience
  // std::vector<arma::umat> chain_clusters(CHAINSIZE, clusters);
  // std::vector<arma::umat> chain_clusterSizes(CHAINSIZE, cluster_sizes);
  // std::vector<arma::mat> chain_mu(CHAINSIZE, mu);
  // std::vector<std::vector<arma::mat> > chain_sigma(CHAINSIZE, sigma);
  
  // for (arma::uword sweep = 0; sweep < CHAINSIZE; ++sweep) {
  //   std::cout << sweep << " K\n" << chain_K[sweep] << std::endl
  // 		<< sweep << " clusters\n" << chain_clusters[sweep] << std::endl
  // 		<< sweep << " sizes\n" << chain_clusterSizes[sweep] << std::endl
  // 		<< sweep << " mu\n" << chain_mu[sweep] << std::endl;
  //   for (arma::uword i = 0; i < N; ++i) { 
  // 	std::cout << sweep << " " << i << " sigma\n" << chain_sigma[sweep][i] << std::endl;
  //   }
  // }
  

  // START CHAIN
  std::cout << "Starting Algorithm with K = " << K << std::endl;
  for (arma::uword sweep = 0; sweep < NUM_SWEEPS; ++sweep) { 
    // shuffle indices
    shuffled_ids = shuffle(ids);
    // std::cout << shuffled_ids << std::endl;

    // SAMPLE CLUSTERS
    for (arma::uword j = 0; j < N; ++j){
      //      std::cout << "j = " << j << std::endl;
      arma::uword i = shuffled_ids(j);
      arma::mat x = X.row(i).t(); // current data point
      
      // Remove i's statistics and any empty clusters
      arma::uword c = clusters(i,0); // current cluster
      cluster_sizes(c,0) -= 1;
      //std::cout << "old c = " << c << std::endl;

      if (cluster_sizes(c,0) == 0) { // remove empty cluster
      	cluster_sizes(c,0) = cluster_sizes(K-1,0); // move entries for K onto position c
	mu.row(c) = mu.row(K-1);
      	sigma[c] = sigma[K-1];
      	uword_dummy(0,0) = c;
	arma::uvec idx = find(clusters == K - 1);
      	clusters.each_row(idx) = uword_dummy;
	cluster_sizes(K-1,0) = 0;
	mu.row(K-1).fill(-999);
	sigma[K-1].fill(-999);
	--K;
      }

      // quick test of logMvnPdf:
      // arma::mat m_(2,1);
      // arma::mat s_(2,2);
      // arma::mat t_(2,1);
      // m_ << 1 << arma::endr << 2;
      // s_ << 3 << -0.2 << arma::endr << -0.2 << 1;
      // t_ << -3 << arma::endr << -3;
      // double lpdf = logMvnPdf(t_, m_, s_);
      // std::cout << lpdf << std::endl; // śhould be -19.1034 (works)


      
      // Find categorical distribution over clusters (tested)
      arma::mat logP(K+1, 1, arma::fill::zeros);
      
      // quick test of logInvWishPdf
      // arma::mat si_(2,2), s_(2,2);
      // double nu_ = 4;
      // si_ << 1 << 0.5 << arma::endr << 0.5 << 4;
      // s_ << 3 << -0.2 << arma::endr << -0.2 << 1;
      // double lpdf = logInvWishPdf(si_, s_, nu_);
      // std::cout << lpdf << std::endl; // should be -7.4399 (it is)

      // quick test for logNormInvWishPdf
      // arma::mat si_(2,2), s_(2,2);
      // arma :: mat mu_(2,1), m_(2,1);
      // double k_ = 0.5, nu_ = 4;
      // si_ << 1 << 0.5 << arma::endr << 0.5 << 4;
      // s_ << 3 << -0.2 << arma::endr << -0.2 << 1;
      // mu_ << -3 << arma::endr << -3;
      // m_ << 1 << arma::endr << 2;
      // double lp = logNormInvWishPdf(mu_,si_,m_,k_,s_,nu_);
      // std::cout << lp << std::endl; // should equal -15.2318 (it is)
      
      // p(existing clusters) (tested)
      for (arma::uword k = 0; k < K; ++k) {
	arma::mat m_ = mu.row(k).t();
	arma::mat s_ = sigma[k];
	logP(k,0) = log(cluster_sizes(k,0)) - log(N-1+alpha) + logMvnPdf(x,m_,s_);
      }

      // p(new cluster): find partition function (tested)
      // arma::mat dummy_mu(D, 1, arma::fill::zeros);
      // arma::mat dummy_sigma(D, D, arma::fill::eye);
      // double logPrior, logLklihd, logPstr, logPartition; 
      // posterior hyperparameters (tested)
      arma::mat m_1(D,1), S_1(D,D);
      double k_1, nu_1;
      k_1 = k_0 + 1;
      nu_1 = nu_0 + 1;
      m_1 = (k_0*m_0 + x) / k_1;
      S_1 = S_0 + x * x.t() + k_0 * (m_0 * m_0.t()) - k_1 * (m_1 * m_1.t());
      // std::cout << k_1 << std::endl
      // 		<< nu_1 << std::endl
      // 		<< m_1 << std::endl
      // 		<< S_1 << std::endl;
      
      // // partition = likelihood*prior/posterior (tested)
      // // (perhaps a direct computation of the partition function would be better)
      // logPrior = logNormInvWishPdf(dummy_mu, dummy_sigma, m_0, k_0, S_0, nu_0);
      // logLklihd = logMvnPdf(x, dummy_mu, dummy_sigma);
      // logPstr = logNormInvWishPdf(dummy_mu, dummy_sigma, m_1, k_1, S_1, nu_1);
      // logPartition = logPrior + logLklihd - logPstr;      
      // std::cout << "log  Prior = " << logPrior << std::endl
      // 		<< "log Likelihood = " << logLklihd << std::endl
      // 		<< "log Posterior = " << logPstr << std::endl
      // 		<< "log Partition = " << logPartition << std::endl;
      
      // Computing partition directly
      double logS0,signS0,logS1,signS1;
      arma::log_det(logS0,signS0,S_0);
      arma::log_det(logS1,signS1,S_1);
      /*std::cout << "log(det(S_0)) = " << logS0 << std::endl
	<< "log(det(S_1)) = " << logS1 << std::endl;*/
      double term1 = 0.5*D*(log(k_0)-log(k_1));
      double term2 = -0.5*D*log(arma::datum::pi);
      double term3 = 0.5*(nu_0*logS0 - nu_1*logS1);
      double term4 = lgamma(0.5*nu_1);
      double term5 = -lgamma(0.5*(nu_1-D));
      double logPartition = term1+term2+term3+term4+term5;
      /*double logPartition = 0.5*D*(log(k_0)-log(k_1)-log(arma::datum::pi)) \
	/+0.5*(nu_0*logS0 - nu_1*logS1) + lgamma(0.5*nu_1) - lgamma(0.5*(nu_1-D));*/
      
      /*      std::cout << "term1 = " << term1 << std::endl
		<< "term2 = " << term2 << std::endl
		<< "term3 = " << term3 << std::endl
		<< "term4 = " << term4 << std::endl
		<< "term5 = " << term5 << std::endl;*/
      
      //std::cout << "logP = " << logPartition << std::endl;

      // p(new cluster): (tested)
      logP(K,0) = log(alpha) - log(N - 1 + alpha) + logPartition;
      //      std::cout << "logP(new cluster) = " << logP(K,0) << std::endl;
      //if(i == 49)
      //assert(false);
      // sample cluster for i
      
      

      arma::uword c_ = logCatRnd(logP);
      clusters(i,0) = c_;
      
      //if (j % 10 == 0){
      //std::cout << "New c = " << c_ << std::endl;
      //std::cout << "logP = \n" << logP << std::endl;
      //}
      // quick test for mvnRnd
      // arma::mat mu, si;
      // mu << 1 << arma::endr << 2;
      // si << 1 << 0.9 << arma::endr << 0.9 << 1;
      // arma::mat m = mvnRnd(mu, si);
      // std::cout << m << std::endl;

      // quick test for invWishRnd
      // double df = 4;
      // arma::mat si(2,2);
      // si << 1 << 1 << arma::endr << 1 << 1;
      // arma::mat S = invWishRnd(si,df);
      // std::cout << S << std::endl;

      if (c_ == K) {	// Sample parameters for any new-born clusters from posterior
	cluster_sizes(K, 0) = 1;
	arma::mat si_ = invWishRnd(S_1, nu_1);
	//arma::mat si_ = S_1;
	arma::mat mu_ = mvnRnd(m_1, si_/k_1);
	//arma::mat mu_ = m_1;
	mu.row(K) = mu_.t();
	sigma[K] = si_;
	K += 1;
      } else {
	cluster_sizes(c_,0) += 1;
      }
      // if (sweep == 0)
      // 	std::cout << " K = " << K << std::endl;
      // // if (j == N-1) {
      // // 	std::cout << logP << std::endl;
      // // 	std::cout << K << std::endl;
      // // 	assert(false);
      // // }
      // std::cout << "K = " << K << "\n" << std::endl;
    }
    
    // sample CLUSTER PARAMETERS FROM POSTERIOR
    for (arma::uword k = 0; k < K; ++k) {
      // std::cout << "k = " << k << std::endl;
      // cluster data
      arma::mat Xk = X.rows(find(clusters == k));
      arma::uword Nk = cluster_sizes(k,0);

      // posterior hyperparameters
      arma::mat m_Nk(D,1), S_Nk(D,D);
      double k_Nk, nu_Nk;
      
      arma::mat sum_k = sum(Xk,0).t();
      arma::mat cov_k(D, D, arma::fill::zeros);
      for (arma::uword l = 0; l < Nk; ++l) { 
	cov_k += Xk.row(l).t() * Xk.row(l);
      }
      
      k_Nk = k_0 + Nk;
      nu_Nk = nu_0 + Nk;
      m_Nk = (k_0 * m_0 + sum_k) / k_Nk;
      S_Nk = S_0 + cov_k + k_0 * (m_0 * m_0.t()) - k_Nk * (m_Nk * m_Nk.t());
      
      // sample fresh parameters
      arma::mat si_ = invWishRnd(S_Nk, nu_Nk);
      //arma::mat si_ = S_Nk;
      arma::mat mu_ = mvnRnd(m_Nk, si_/k_Nk);
      //arma::mat mu_ = m_Nk;
      mu.row(k) = mu_.t();
      sigma[k] = si_;
    }
    std::cout << "Iteration " << sweep + 1 << "/" << NUM_SWEEPS<< " done. K = " << K << std::endl;
        
    // // STORE CHAIN
    // if (SAVE_CHAIN) {
    //   if (sweep >= BURN_IN) { 
    // 	chain_K[sweep - BURN_IN] = K;
    // 	chain_clusters[sweep - BURN_IN] = clusters;
    // 	chain_clusterSizes[sweep - BURN_IN] = cluster_sizes;
    // 	chain_mu[sweep - BURN_IN] = mu;
    // 	chain_sigma[sweep - BURN_IN] = sigma;
    //   }
    // }
	
  }
  std::cout << "Final cluster sizes: " << std::endl
	    << cluster_sizes.rows(0, K-1) << std::endl;






  
  // WRITE OUPUT DATA TO FILE
  arma::mat MU = mu.rows(0,K-1);
  arma::mat SIGMA(D*K,D);
  for (arma::uword k = 0; k < K; ++k) { 
    SIGMA.rows(k*D,(k+1)*D-1) = sigma[k];
  }
  arma::umat IDX = clusters;

  // A) toycluster data
  // char MuFile[] = "../data_files/toyclusters/dpmMU.out";
  // char SigmaFile[] = "../data_files/toyclusters/dpmSIGMA.out";
  // char IdxFile[] = "../data_files/toyclusters/dpmIDX.out";

  // B) X4.dat
  char MuFile[] = "dpmMU.out";
  char SigmaFile[] = "dpmSIGMA.out";
  char IdxFile[] = "dpmIDX.out";
  std::ofstream KFile("K.out");
  
  MU.save(MuFile, arma::raw_ascii);
  SIGMA.save(SigmaFile, arma::raw_ascii);
  IDX.save(IdxFile, arma::raw_ascii);
  KFile << "K = " << K << std::endl;
  
  if (SAVE_CHAIN) {}
  //   std::ofstream chainKFile("chainK.out");
  //   std::ofstream chainClustersFile("chainClusters.out");
  //   std::ofstream chainClusterSizesFile("chainClusterSizes.out");
  //   std::ofstream chainMuFile("chainMu.out");
  //   std::ofstream chainSigmaFile("chainSigma.out");
    
  //   chainKFile << "Dirichlet Process Mixture Model.\nInput: " << inputFile << std::endl
  // 	       << "Number of iterations of Gibbs Sampler: " << NUM_SWEEPS << std::endl
  // 	       << "Burn-In: " << BURN_IN << std::endl
  // 	       << "Initial number of clusters: " << initial_K << std::endl
  // 	       << "Output: Number of cluster (K)\n" << std::endl; 
  //   chainClustersFile << "Dirichlet Process Mixture Model.\nInput: " << inputFile << std::endl
  // 		      << "Number of iterations of Gibbs Sampler: " << NUM_SWEEPS << std::endl
  // 		      << "Burn-In: " << BURN_IN << std::endl
  // 		      << "Initial number of clusters: " << initial_K << std::endl
  // 		      << "Output: Cluster identities (clusters)\n" << std::endl; 
  //   chainClusterSizesFile << "Dirichlet Process Mixture Model.\nInput: " << inputFile << std::endl
  // 			  << "Number of iterations of Gibbs Sampler: " << NUM_SWEEPS << std::endl
  // 			  << "Burn-In: " << BURN_IN << std::endl
  // 			  << "Initial number of clusters: " << initial_K << std::endl
  // 			  << "Output: Size of clusters (cluster_sizes)\n" << std::endl; 
  //   chainMuFile << "Dirichlet Process Mixture Model.\nInput: " << inputFile << std::endl
  // 		<< "Number of iterations of Gibbs Sampler: " << NUM_SWEEPS << std::endl
  // 		<< "Burn-In: " << BURN_IN << std::endl
  // 		<< "Initial number of clusters: " << initial_K << std::endl
  // 		<< "Output: Samples for cluster mean parameters (mu. Note: means stored in rows)\n" << std::endl; 
  //   chainSigmaFile << "Dirichlet Process Mixture Model.\nInput: " << inputFile << std::endl
  // 		   << "Number of iterations of Gibbs Sampler: " << NUM_SWEEPS << std::endl
  // 		   << "Burn-In " << BURN_IN << std::endl
  // 		   << "Initial number of clusters: " << initial_K << std::endl
  // 		   << "Output: Samples for cluster covariances (sigma)\n" << std::endl; 


  //   for (arma::uword sweep = 0; sweep < CHAINSIZE; ++sweep) {
  //     arma::uword K = chain_K[sweep];
  //     chainKFile << "Sweep #" << BURN_IN + sweep + 1 << "\n" << chain_K[sweep] << std::endl;
  //     chainClustersFile << "Sweep #" << BURN_IN + sweep + 1 << "\n" << chain_clusters[sweep]  << std::endl;
  //     chainClusterSizesFile << "Sweep #" << BURN_IN + sweep + 1 << "\n" << chain_clusterSizes[sweep].rows(0, K - 1) << std::endl;
  //     chainMuFile << "Sweep #" << BURN_IN + sweep + 1 << "\n" << chain_mu[sweep].rows(0, K - 1) << std::endl;
  //     chainSigmaFile << "Sweep #" << BURN_IN + sweep + 1<< "\n";
  //     for (arma::uword i = 0; i < K; ++i) { 
  // 	chainSigmaFile << chain_sigma[sweep][i] << std::endl;
  //     }
  //     chainSigmaFile << std::endl;
  //   }
  // }

  return 0;
}
// The number of users should always be a positive integer.
// The number of movies should always be a positive integer.
// The number of features should always be a positive integer.
int CollaborativeFiltering::ComputeGradient(const DataUnlabeled &ratings_data,
  const DataUnlabeled &indicator_data,int num_users,int num_movies,
  int num_features) {
  assert(num_users >= 1);
  assert(num_movies >= 1);
  assert(num_features >= 1);
  const int kTotalNumFeatures = num_features*(num_users+num_movies);
  const arma::vec kCurrentTheta = theta();
  arma::mat features_cvec = arma::zeros<arma::mat>(num_movies*num_features,1);
  arma::mat params_cvec = arma::zeros<arma::mat>(num_users*num_features,1);
  for(int feature_index=0; feature_index<kTotalNumFeatures; feature_index++)
  {
    if (feature_index < (num_users*num_features)) {
      params_cvec(feature_index) = kCurrentTheta[feature_index];
    }
    else {
      features_cvec(feature_index-(num_users*num_features)) = \
        kCurrentTheta[feature_index];
    }
  }
  arma::mat features_cvec_squared = arma::square(features_cvec);
  arma::mat params_cvec_squared = arma::square(params_cvec);
  arma::mat params_mat = arma::reshape(params_cvec,num_users,num_features);
  arma::mat features_mat = \
    arma::reshape(features_cvec,num_movies,num_features);
  const arma::mat kSubsetIndicatorMat = \
    indicator_data.training_features().submat(0,0,num_movies-1,num_users-1);
  const arma::mat kSubsetRatingsMat = \
    ratings_data.training_features().submat(0,0,num_movies-1,num_users-1);
  const arma::mat kYMat = \
    (arma::ones<arma::mat>(num_users,num_movies)-kSubsetIndicatorMat.t()) % \
    (params_mat*features_mat.t())+kSubsetRatingsMat.t();
  const arma::mat kDiffMat = (params_mat*features_mat.t()-kYMat).t();
  arma::mat grad_params_arr = arma::zeros<arma::mat>(num_users*num_features,1);
  arma::mat grad_params_arr_reg = \
    arma::zeros<arma::mat>(num_users*num_features,1);
  for(int grad_index=0; grad_index<(num_users*num_features); grad_index++)
  {
    int user_index = 1+(grad_index % num_users);
    int feature_index = 1+((grad_index-(grad_index % num_users))/num_users);
    grad_params_arr(grad_index) = \
      arma::as_scalar(sum(kDiffMat.col(user_index-1) % \
      features_mat.col(feature_index-1)));
    grad_params_arr_reg(grad_index) = \
      grad_params_arr(grad_index)+lambda_*params_cvec(grad_index);
  }
  arma::mat grad_features_arr = \
    arma::zeros<arma::mat>(num_movies*num_features,1);
  arma::mat grad_features_arr_reg = \
    arma::zeros<arma::mat>(num_movies*num_features,1);
  for(int grad_index=0; grad_index<(num_movies*num_features); grad_index++)
  {
    int movie_index = 1+(grad_index % num_movies);
    int feature_index = 1+((grad_index-(grad_index % num_movies))/num_movies);
    grad_features_arr(grad_index) = \
      arma::as_scalar(sum(kDiffMat.row(movie_index-1) % \
      (params_mat.col(feature_index-1)).t()));
    grad_features_arr_reg(grad_index) = \
      grad_features_arr(grad_index)+lambda_*features_cvec(grad_index);
  }
  arma::vec gradient_array_reg = arma::zeros<arma::vec>(kTotalNumFeatures);
  gradient_array_reg.subvec(0,(num_users*num_features-1)) = \
    grad_params_arr_reg;
  gradient_array_reg.subvec(num_users*num_features,kTotalNumFeatures-1) = \
    grad_features_arr_reg;
  set_gradient(gradient_array_reg);

  return 0;
}
Exemple #22
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/** Internal function that gives the output in c++ way (writes into allocated memory).
 * See glm_ridge_c for a wrapper that is being called from R.
 */
void glm_ridge( vec& beta,      // output: regression coefficients (contains intercept)
                double& loss,   // output: value of the loss function
                vec& w, 				// output: weights of the pseudo-gaussian observations at the optimum (needed for Student-t model)
                int& qau,       // output: number of quadratic approximation updates 
                arma::mat x,
                Function pseudo_obs,
                double lambda,
                bool intercept,
                arma::vec penalty, // relative penalties for the variables
                double thresh,
                int qa_updates_max,
                int ls_iter_max=50,
                bool debug=false)
{
  
  if (intercept) {
    // add a vector of ones to x and set zero penalty for the intercept
    x = join_horiz(ones<vec>(x.n_rows), x);
    penalty = join_vert(zeros<vec>(1), penalty); 
  }
  
  int n = x.n_rows;
  int D = x.n_cols;
  int ls_iter; // counts linesearch iterations
  int j;
  double t; // step size in line search 
  double a = 0.1; // backtracking line search parameters a and b (see Boyd and Vandenberghe, 2004)
  double b = 0.5; 
  
  // initialization
  vec beta_new(D); beta_new.zeros();
  vec dbeta(D); dbeta.zeros();
  vec grad(D); grad.zeros(); // gradient of the negative log likelihood w.r.t. the regression coefficients
  vec grad_f(n); grad_f.zeros(); // pointwise gradient of the negative log likelihood w.r.t. the latent values f
  vec f = x*beta;
  
  mat xw(n,D); // this will be the weighted x
  mat regmat = lambda*diagmat(penalty);//eye(D,D); // regularization matrix
  
  // initial quadratic approximation
  List obs = pseudo_obs(f,w);
  vec z = as<vec>(obs["z"]);
  w = as<vec>(obs["w"]);
  grad_f = as<vec>(obs["grad"]);
  double loss_initial = ((double) obs["loss"]) + elnet_penalty(beta, lambda, 0, penalty);
  double loss_old = loss_initial; // will be updated iteratively
  loss = loss_initial; // will be updated iteratively
  double tol = thresh*fabs(loss_initial); // threshold for convergence
  double decrement = 0; // newton decrement, used to monitor convergence
  
  qau = 0;
  while (qau < qa_updates_max) {
    
    // weight the observations
    for (j=0; j<D; ++j)
      xw.col(j) = x.col(j) % sqrt(w);
    
    // weighted least squares solution
    beta_new = solve( xw.t()*xw + regmat, xw.t()*(sqrt(w)%z) ); 
    dbeta = beta_new - beta;
    grad = x.t()*grad_f + lambda*penalty%beta; // gradient of negative log likelihood + gradient of penalty
    decrement = -sum(grad%dbeta); // newton decrement
    
    // check for convergence
    if (decrement < tol)
    	break;
    
    // backtracking line search
    t = 1.0/b;
    
    ls_iter = 0;
    
    while (ls_iter < ls_iter_max) {
      
      t = b*t;
      f = x*(beta+t*dbeta);
      obs = pseudo_obs(f,w);
      loss = ((double) obs["loss"]) + elnet_penalty(beta+t*dbeta, lambda, 0, penalty);
      ++ls_iter;
      
      if (std::isnan(loss))
        continue;
      
      if (decrement > 0) {
      	if (loss < loss_old - a*t*decrement )
      		break;
      } else {
      	Rcpp::Rcout << "The search direction is not a descent direction ";
      	Rcpp::Rcout << "(newton decrement = " << decrement << ", should be positive), ";
      	Rcpp::Rcout << ", this is likely a bug. Please report to the developers." << '\n';
      }
    }
    
    if (ls_iter == ls_iter_max && ls_iter_max > 1) {
      // beta.print("beta = ");
      // dbeta.print("dbeta = ");
      // grad.print("grad = ");
      // Rcpp::Rcout << "loss = " << loss << "\n";
      // Rcpp::Rcout << "loss_initial = " << loss_initial << "\n";
      // Rcpp::Rcout << "tol = " << tol << "\n";
      // Rcpp::Rcout << "decrement = " << decrement << "\n";
      // Rcpp::Rcout << "\n\n";
      Rcpp::Rcout << "glm_ridge warning: maximum number of line search iterations reached. The optimization can be ill-behaved.\n";
      break;
    }
    
    // update the solution
    beta = beta + t*dbeta;
    z = as<vec>(obs["z"]);
    w = as<vec>(obs["w"]);
    grad_f = as<vec>(obs["grad"]);
    loss_old = loss;
    ++qau;
  }
  
  if (qau == qa_updates_max && qa_updates_max > 1) {
  	if (decrement/fabs(loss_initial) > 100*tol) {
			// warn the user if the max number of iterations is reached and we are relatively far
			// (two orders of magnitude) from the given convergence threshold 
  		Rcpp::Rcout << "glm_ridge warning: maximum number of quadratic approximation updates reached, within ";
  		Rcpp::Rcout << decrement << " from optimum (tolerance = " << thresh << ").\n";
  	}
  }
}
// funcao FFBS para regressao com V constante e fator de desconto
Rcpp::List drmOnly1FFBSdiscW(arma::mat Y, arma::mat X, arma::mat dV, double discW,
                             arma::vec m0, arma::mat ZC0) {
    int T = Y.n_rows; // ATENCAO: matriz de dados deve entrar T x q!!
    int q = Y.n_cols;
    int r = q*X.n_cols; // ATENCAO: matriz de exogenas deve entrar sendo T x p

    mat Yt = Y.t();
    mat I_q = diagmat(ones(q));

// FORWARD FILTERING

    mat mm(r, T+1);
    vec aa(r);//nao e' preciso armazenar aa_t
    mat RR(r, r);//nao e' preciso armazenar RR_t
    vec ff(q); //nao e' preciso armazenar ff
    mat QQ(q, q); //nao e' preciso armazenar seus valores
    mat AA;
    mat ee;
    mat FF;

//para previsao, e' preciso armazenar W_{T+1}
    mat dVInv = inv(dV);

//parametros para forma quadrada
    mat ZR;
    mat ZC(r, r); //utilizado para fazer a amostragem retrospectiva

//objetos para decomposicao em valores singulares e espectral
    mat L, Eigvec;
    vec eigval;

    double sqrtDiscW = sqrt(discW);
    double sqrt1mDiscW = sqrt(1-discW);

//para evitar o loop da amostragem retrospectiva, recorri a uma propriedade
//do FFBS com o uso do fator de desconto.
//O que observei e' que
//th_{t-k} = (1-delta) \sum delta^j m_{t-k+j} + delta^k m_T + \sum delta^j e_{T-k+j}
//IntegerVector seq0toT = seq_len(T+1)-1;
//vec powDiscW = exp(log(discW)*as<NumericVector>(seq0toT));
//mat Dmat(T+1, T+1); Dmat.zeros();

//valores aleatorios gerados
    mat th = randn(r, T+1);

    mm.col(0) = m0;
    ZC = ZC0;
    th.col(0) = sqrt1mDiscW*ZC*th.col(0);
//Dmat.submat(0, 0, T, 0) = powDiscW.subvec(0, T);

    for (int k = 1; k < (T+1); k++) {
        //evolucao
        aa = mm.col(k-1);
        ZR = ZC/sqrtDiscW;
        RR = ZR * ZR.t();

        //predicao
        FF = kron(I_q, X.row(k-1)).t();
        ff = FF.t()*aa;
        QQ = symmatu(FF.t() * RR * FF + dV);

        //atualizacao

        L = ZR.t()*FF; //forma raiz quadrada
        eig_sym(eigval, Eigvec, L * dVInv * L.t());
        ZC = ZR * Eigvec * diagmat(1.0/sqrt(eigval + 1.0));

        AA = ZC*ZC.t()*FF*dVInv; //p.105 West & Harrison (1997)
        ee = Yt.col(k-1) - ff;

        mm.col(k) = aa + AA*ee;

        th.col(k) = sqrt1mDiscW*ZC*th.col(k);
        mm.col(k-1) -= discW*mm.col(k-1); //mm agora representa mm*
        //Dmat.submat(k, k, T, k) = powDiscW.subvec(0, T-k);
    }

// BACKWARD SAMPLING
//simulacao dos estados sem loop
    /*
    th = (mm+th)*Dmat;
    rowvec oneP = ones(X.n_cols);
    mat Mu = kron(I_q, oneP) * (th.cols(1, T) % repmat(X.t(), q, 1));
    */
    mat Mu(q, T);
    th.col(T) += mm.col(T);
    for(int k = 0; k < T; k++) {
        th.col(T-1-k) += mm.col(T-1-k) + discW*th.col(T-k);
        Mu.col(T-1-k) = kron(I_q, X.row(T-1-k))*th.col(T-k);
    }
    return Rcpp::List::create(Named("th") = th, Named("Mu") = Mu.t(),
                              Named("ZW") = sqrt((1-discW)/discW)*ZC);
}
// [[Rcpp::export]]
Rcpp::List getWEXPcutoff(arma::mat data, arma::mat subdata, arma::mat Y, arma::mat subY, int N, arma::mat RT_out, double predictTime, arma::vec resid_sco, double fitvar, arma::colvec cutoffs){

   
   //create dataD
   arma::mat dataDuns = data.rows(find(data.col(1)==1));
   arma::mat dataD = dataDuns.rows(sort_index(dataDuns.col(0)));


   int n = data.n_rows, nD = dataD.n_rows, np = Y.n_cols, ncuts = subdata.n_rows; 
   //guide
    colvec times = data.col(0); 
   // status= data.col(1); 
   // Dtimes = dataD.col(0); 
   // weights = data.col(4); 
   //  Dweights = dataD.col(4); 

   uvec tmpind = find((data.col(0) <= predictTime)%data.col(1)); // indices of (data$times<=predict.time)&(data$status==1)
   mat myempty(1,1); 
   uvec tmpindT = conv_to<uvec>::from(CSumI(times.elem(tmpind), 4, dataD.col(0), myempty,  FALSE)); 


   colvec rrk =  exp(data.col(6)); //data.col(6)  is data$linearY
   
   // build riskmat
   mat riskmat(n, nD); 
   mat::iterator riskmat_it = riskmat.begin(); 
 
for(colvec::iterator j = dataD.begin_col(0); j != dataD.end_col(0); j++){   
   for( colvec::iterator i = data.begin_col(0); i != data.end_col(0); i++){
       *riskmat_it = *i >= *j; riskmat_it++;
      }  
   }   
   //s0 and s1
   colvec s0 = riskmat.t()*(rrk%data.col(4)); 
   colvec s1 = riskmat.t()*trans(Vec2Mat(rrk%data.col(4), np)%Y.t()); 

   //haz0 and cumhaz0
   
   colvec haz0 = dataD.col(4)/sum(riskmat%trans(Vec2Mat(rrk%data.col(4), nD))).t(); 
   colvec cumhaz0 = cumsum(haz0); 
   colvec ptvec(1); ptvec(0) = predictTime; 
   colvec cumhaz_t0 = CSumI(ptvec, 4, dataD.col(0), haz0, TRUE); 

   //Wexp
   colvec Wexp_beta = resid_sco*fitvar*N; 

   colvec WexpLam1(n); WexpLam1.zeros(n); 
   WexpLam1(tmpind) =  N/s0(tmpindT - 1);     
   WexpLam1 = WexpLam1 - CSumI( myPmin(data.col(0), predictTime), 4, dataD.col(0), haz0/s0, TRUE)%rrk*N; 
 
   colvec WexpLam2 = Wexp_beta*CSumI(ptvec, 4, dataD.col(0), haz0%s1/trans(Vec2Mat(s0, np)), TRUE); 
   colvec WexpLam = WexpLam1 - WexpLam2; 

   //Fyk = Pr(Sy < c)
   colvec Fyk = CSumI( cutoffs, 4, data.col(6), data.col(4), TRUE)/sum(data.col(4)); 

   colvec dFyk(Fyk.n_elem); dFyk(0) = 0;
   dFyk(span(1, Fyk.n_elem - 1)) = Fyk(span(0, Fyk.n_elem-2));
   dFyk = Fyk - dFyk; 
   
   colvec Sy = subdata.col(5); 
   colvec Syall = data.col(5); 
   colvec St0_Fyk = cumsum(Sy%dFyk); 
   double St0 = max(St0_Fyk); 
   colvec St0_Syk = St0 - St0_Fyk; 
 //
  mat Wexp_Cond_Stc =  -Vec2Mat(Sy%exp(subdata.col(6)), n)%(trans(Vec2Mat(WexpLam, ncuts)) +as_scalar(cumhaz_t0)*Wexp_beta*subY.t()); 

  mat tmpmat = conv_to<mat>::from(trans(Vec2Mat(data.col(6), ncuts)) > Vec2Mat(cutoffs, n)); 
  mat Wexp_Stc = trans(CSumI(cutoffs, 0, subdata.col(6), Wexp_Cond_Stc.t()%Vec2Mat(dFyk, n).t(), TRUE)) + trans(Vec2Mat(Syall,ncuts))%tmpmat - Vec2Mat(St0_Syk, n); 

  colvec Wexp_St = sum(trans(Wexp_Cond_Stc)%trans(Vec2Mat(dFyk, n))).t() + Syall - St0; 

   mat Wexp_Fc = 1-tmpmat - Vec2Mat(Fyk, n); 

   //assemble for classic performance measures, given linear predictor

   List out(8); 

   out[0] = -Wexp_Cond_Stc; 
   out[1] =  Wexp_Fc;
   mat Wexp_St_mat = Vec2Mat(Wexp_St, ncuts).t(); 

   out[2] = (-Wexp_St_mat%Vec2Mat(RT_out.col(3), n) + Wexp_Stc)/St0; 
   out[3] = (Wexp_St_mat%Vec2Mat(RT_out.col(4), n) -Wexp_Fc - Wexp_Stc)/(1-St0); 

   out[4] = -Wexp_St; 
   out[5] = (Wexp_St_mat - Wexp_Stc - Vec2Mat(RT_out.col(6), n)%Wexp_Fc)/Vec2Mat(Fyk, n); 
   out[6] = (Vec2Mat(RT_out.col(5)-1, n)%Wexp_Fc - Wexp_Stc)/Vec2Mat(1-Fyk, n);
   out[7] = Wexp_beta;

   return out; 
}
Exemple #25
0
Rcpp::List irls_binomial_cpp_fast_br(arma::mat A, arma::vec b, double maxit, double tol)
{
//Def
arma::vec x;
x.zeros(A.n_cols,1);
arma::vec xold;
arma::mat varmatrix;

double nobs;
nobs = A.n_rows;
double df;
df = A.n_cols;
double n;

double ll;
double aic;
double bic;
double mdl;



arma::vec W(nobs);
arma::vec unit(nobs);
unit.ones(nobs);
arma::vec eta(nobs);
arma::vec g(nobs);
arma::vec gprime(nobs);
arma::vec z(nobs);
//mod
arma::vec bprime(nobs);

//int k;

for (int i = 0; i < maxit; ++i) {
  eta = A * x;
  
  for (int j=0; j < nobs; ++j) {
    g[j] = 1.0 / (1.0 + exp(-1.0 * eta[j]));
    gprime[j] = exp (-1.0 * eta[j]) / ((1.0 + exp (-1.0 * eta[j])) * (1.0 + exp (-1.0 * eta[j])));
    //mod
    bprime[j] = (b[j]+(df/nobs)*(0.5))/(1+(df/nobs));
    //bprime[j] = b[j]+(sum(b)/nobs)*(0.5);
  }
     
  //z = eta+(b-g)/gprime;
  z = eta+(bprime-g)/gprime;
  
  W = (gprime % gprime);
  W /= (g % (unit-g)); 
  //W += unit;
  xold = x;
  
  //coefficients
  //x = arma::solve(A.t()*(W % A.each_col()), A.t()*(W % z), arma::solve_opts::no_approx);
  varmatrix = A.t()*(W % A.each_col());
  x = arma::solve(varmatrix, A.t()*(W % z), arma::solve_opts::no_approx);
  //k = i;
  
if(sqrt(arma::dot(x-xold,x-xold)) < tol){
 break;
}}

n = A.n_rows;

//arma::vec e;
//double ssr;
//e = (b - A*x);
//e = (bprime - A*x);
//ssr = accu(e.t()*e);

//scores

//ll = arma::accu(-arma::dot(b,log(unit + exp(-(A*x)))) - arma::dot((unit-b),log(unit + exp(A*x))));
ll = arma::accu(-arma::dot(b,log(unit + exp(-(A*x)))) - arma::dot((unit-b),log(unit + exp(A*x))));

aic = - 2 * ll + 2 * df;

bic = - 2 * ll + log(nobs) * df;

//mdl

// arma::mat xz;
// xz.zeros(size(x));
// 
// arma::vec ez;
// double ssrz;
// double ssrtot;
// double RR;
// double F;
// double mdl;
// arma::vec yaverage(n);
// 
// ez = (b - A*xz);
// ssrz = accu(ez.t()*ez);
// F = (((ssrz - ssr)/df)/(ssr/((n-(df + 1)))));
// 
// for (int j=0; j < n; ++j) {
// yaverage[j] = b[j] - arma::mean(b);
// }
// 
// ssrtot = accu(yaverage.t()*yaverage);
// 
// RR = 1-(ssr/ssrtot);
// 
// if (RR > (df/n)) {
// mdl = (n/2) * log(ssr/(n-df)) + (df/2) * log(F) + log(n);
// } else {
// mdl = (n/2) * log((accu(b.t()*b))/n) + 0.5 * log(n);
// }

//return
return Rcpp::List::create(
  Rcpp::Named("loglik") = ll,
  Rcpp::Named("aic") = aic,
  Rcpp::Named("bic") = bic,
  Rcpp::Named("mdl") = mdl
);

}
Exemple #26
0
void kalmanFilter::setMeasurement(arma::mat M) {
	measurementMatrix = M;
	measurementMatrixT = M.t();
}
Exemple #27
0
///
/// \brief Vespucci::Math::DimensionReduction::VCA
/// Vertex Component Analysis
/// \param R The dataset
/// \param endmembers Number of endmembers to compute
/// \param indices Row indices of pure components.
/// \param endmember_spectra Spectra of pure components (note that these are in
/// columns, not rows as in spectra_)
/// \param projected_data Projected data
/// \param fractional_abundances Purity of a given spectrum relative to endmember
/// \return Convergeance (no actual test implemented...)
///
bool Vespucci::Math::DimensionReduction::VCA(const arma::mat &R, arma::uword p,
         arma::uvec &indices, arma::mat &endmember_spectra,
         arma::mat &projected_data, arma::mat &fractional_abundances)
{
//Initializations
    arma::uword L = R.n_rows;
    arma::uword N = R.n_cols;
    if (L == 0 || N == 0){
        std::cerr << "No data!" << std::endl;
        return false;
    }

    if (p > L){
        std::cerr << "wrong number of endmembers (" << p << ")!"<< std::endl;
        std::cerr << "set to 5 or one less than number of spectra" << std::endl;
        p = (L < 5? 5: L-1);
    }
//mat of SNR
    arma::mat r_m = mean(R, 1);
    arma::mat R_m = arma::repmat(r_m, 1, N); //the mean of each spectral band
    arma::mat R_o = R - R_m; //mean-center the data
    arma::mat Ud;
    arma::vec Sd;
    arma::mat Vd;
    //arma::svds(Ud, Sd, Vd, arma::sp_mat(R_o * R_o.t()/N), p);
    Vespucci::Math::DimensionReduction::svds(R_o*R_o.t()/N, p, Ud, Sd, Vd);
    arma::mat x_p;
    try{
    x_p = Ud.t() * R_o;
    }catch(std::exception e){
        std::cout << "Ud.t() * R_o" << std::endl;
    }

    double SNR = Vespucci::Math::DimensionReduction::estimate_snr(R, r_m, x_p);
    double SNR_th = 15 + 10*log10(p);

//Choose projective projection or projection to p-1 subspace
    arma::mat y;
    if (SNR < SNR_th){
        arma::uword d = p - 1;
        Ud = Ud.cols(0, d-1);
        projected_data = Ud * x_p.rows(0, d-1) + R_m; //in dimension L
        arma::mat x = x_p.rows(0, d-1);//x_p = trans(Ud)*R_o, p-dimensional subspace
        //following three lines are one in arma::matlab...
        arma::mat sum_squares = sum(pow(x, 2));
        double c = sum_squares.max();
        c = std::sqrt(c);
        y = arma::join_vert(x, c*arma::ones(1, N));
      }
    else{
        arma::uword d = p;
        Vespucci::Math::DimensionReduction::svds(R*R.t()/N, p, Ud, Sd, Vd);
        arma::svds(Ud, Sd, Vd, arma::sp_mat(R*R.t()/N), d);//R_o is a mean centered version...
        x_p = Ud.t() * R;
        projected_data = Ud * x_p.rows(0, d-1);
        arma::mat x = Ud.t() * R;
        arma::mat u = arma::mean(x, 1);
        y = x / arma::repmat(sum(x % arma::repmat(u, 1, N)), d, 1);
    }


    // The VCA algorithm
    arma::vec w;
    w.set_size(p);
    arma::vec f;
    arma::rowvec v;
    indices.set_size(p);
    //there are no fill functions for arma::uvecs
    for (arma::uword i = 0; i < p; ++i)
        indices(i) = 0;

    arma::mat A = arma::zeros(p, p);
    double v_max;
    double sum_squares;
    arma::uvec q1;
    A(p-1, 0) = 1;
    for (arma::uword i = 0; i < p; ++i){
        w.randu();
        f = w - A*arma::pinv(A)*w;
        sum_squares = sqrt(sum(square(f)));
        f /= sum_squares;
        v = f.t() * y;
        v_max = arma::max(abs(v));
        q1 = arma::find(abs(v) == v_max, 1);
        indices(i) = q1(0);
        A.col(i) = y.col(indices(i)); //same as x.col(indices(i));
    }
    endmember_spectra = projected_data.cols(indices);
    fractional_abundances = arma::trans(pinv(endmember_spectra) * projected_data);
    return true;
}
Exemple #28
0
CVXOBJ cvxObj(double t, arma::mat Postprob, arma::rowvec wght, arma::mat x, arma::mat y, arma::mat n, arma::mat ab, 
                 arma::mat F, arma::vec h, unsigned int N, unsigned int Nrep ){
   unsigned int m = F.n_rows;
   unsigned int K = Postprob.n_cols;
   arma::vec d(m);
   arma::mat D(m,m);
   arma::mat J(2,K);
   arma::mat H_d(2,K);
   arma::mat H_o(2,K);
   arma::mat n_ab(N,Nrep*K);
   arma::mat x_a(N,Nrep*K);
   arma::mat y_b(N,Nrep*K);
   arma::mat dn_ab(K,K);
   arma::mat dx_a(K,K);
   arma::mat dy_b(K,K);
   arma::mat px(N,K);
   // List out(3);
   double f;
   arma::vec g(2*K);
   arma::mat H(2*K,2*K);
   J.zeros();
   H_d.zeros();
   H_o.zeros();

   d = F * vectorise(ab) - h;
   D = diagmat(1 / d);
   n_ab = N_ab(n,sum(ab,0));
   x_a = N_ab(x,ab.row(0));
   y_b = N_ab(y,ab.row(1));

   J =mydigamma( ones(2,1) * sum(ab,0) ) % (ones(2,1)*wght) * Nrep;
   cmpDgm(N_ab(n,sum(ab,0)),K).t() * Postprob;
  mydigamma(ab) % (ones(2,1)*wght) *Nrep;
   dn_ab = cmpDgm(n_ab,K).t() * Postprob;
   dx_a = cmpDgm(x_a,K) .t() * Postprob;
   dy_b = cmpDgm(y_b,K) .t() * Postprob;

   J =mydigamma( ones(2,1) * sum(ab,0) ) % (ones(2,1)*wght) * Nrep -  
      mydigamma(ab) % (ones(2,1)*wght) *Nrep;
   for (unsigned int i=0;i<K;i++){
     J(0,i) += dx_a(i,i) - dn_ab(i,i);
     J(1,i) += dy_b(i,i) - dn_ab(i,i);
   }
   // compute the trigamma for hessian
   // repeatedly use dn_ab, dx_a, dy_b; H_d represents the diagnal; H_o off diagnal of H
   dn_ab = cmpTgm(n_ab,K).t() * Postprob;
   dx_a = cmpTgm(x_a,K) .t() * Postprob;
   dy_b = cmpTgm(y_b,K) .t() * Postprob;

   H_d = mytrigamma( ones(2,1) * sum(ab,0) ) % (ones(2,1)*wght) * Nrep -  
       mytrigamma(ab) % (ones(2,1)*wght) *Nrep;
   for (unsigned int i=0;i<K;i++){
     H_d(0,i) += dx_a(i,i) - dn_ab(i,i); //
     H_d(1,i) += dy_b(i,i) - dn_ab(i,i);
   }
   H_o = ( mytrigamma( ones(2,1) * sum(ab,0) ) % (ones(2,1)*wght) * Nrep ) - ones(2,1) * dn_ab.diag().t();
   H = diagmat(vectorise(H_d));
   for(unsigned int i=0;i<K;i++){
       H(2*i,1+2*i) = H_o(1,i);
       H(1+2*i,2*i) = H_o(1,i);
   }

   // likelihood computation 
   px = Nrep*mylgamma(ones(N,1)*sum(ab,0)) - Nrep*mylgamma(ones(N,1)*ab.row(0)) - Nrep*mylgamma(ones(N,1)*ab.row(1))
         - cmpLgm(n_ab,K) + cmpLgm(x_a,K) + cmpLgm(y_b,K);

   g = -t * vectorise(J) - F.t() * D * ones(m,1); // g first dierivatives of the function
   H = -t * H;        // H Hessian
   for (unsigned int i=0;i<m;i++){
      d(i) =  log(-d(i));
   }
   f = -t * accu(px % Postprob) - sum(d); // f value for output function

   return {g,H,f};

}
Exemple #29
0
//' Matrix left-multiplied by its transpose
//' 
//' Given matrix A, the procedure returns A'A.
//' 
//' @param x Numeric matrix.
// [[Rcpp::export]]
arma::mat tmult(arma::mat x) {
	return(x.t()*x);
}
Exemple #30
0
//[[Rcpp::export]]
List cmpHmm(const arma::mat x, arma::mat y, arma::mat trans, arma::mat ab, arma::mat F, arma::vec h){
 unsigned int Nrep = x.n_cols;
 unsigned int K = ab.n_cols;
 unsigned int N = x.n_rows;
 unsigned int Nit = 30;
 double t_step;
 double mu = 1e6;
 double PRECISION = 1e8;
 double t_INITIAL = 1;
 double ALPHA = 0.1;
 double BETA = 0.7;
 double NTTOL = 1e-6;
 double s;
 double lambda;
 List out(4);

 CVXOBJ cvx;
 CVXOBJ cvx_new;

 arma::mat n = x + y;
 arma::mat Dens(N,K);
 arma::mat Forward(N,K);
 arma::mat Backward(N,K);
 arma::mat Postprob(N,K);
 arma::rowvec wght(K);
 arma::vec Scale(N);
 Backward.row(N-1).fill(0);
 Scale(0) = 1.0;
 arma::vec logl;
 logl.zeros(Nit+1);
 arma::vec v(2*K); // inverse(H)*J

 for(unsigned int nit=0;nit<Nit;nit++){
      
      Dens = exp(  Nrep*mylgamma(ones(N,1)*sum(ab,0)) - Nrep*mylgamma(ones(N,1)*ab.row(0)) - Nrep*mylgamma(ones(N,1)*ab.row(1))
         - cmpLgm(N_ab(n,sum(ab,0)),K) + cmpLgm(N_ab(x,ab.row(0)),K) + cmpLgm(N_ab(y,ab.row(1)),K)
         + mylgamma(n+1.0) * ones(Nrep,K) - mylgamma(x+1.0) * ones(Nrep,K) - mylgamma(y+1.0) * ones(Nrep,K) 
         );

      Forward.row(0) =  Dens.row(0)/K;
      for (unsigned int n=1;n<N;n++){
         Forward.row(n) = ( Forward.row(n-1) * trans ) % Dens.row(n);
         Scale(n) = sum(Forward.row(n));
         Forward.row(n) = Forward.row(n) / Scale(n);
      }
      logl(nit+1) = log(sum(Forward.row(N-1))) + sum(logvec(Scale,N)); // caculate the likelhood remember end at N-1

      Backward.row(N-1) += 1;
      for (int n=N-2;n>=0;n--){
         Backward.row(n) = ( Backward.row(n+1) % Dens.row(n+1) ) * trans.t();
         Backward.row(n) = Backward.row(n) / Scale(n);
      }
      
      trans = trans % ( Forward.rows(0,N-2).t() * ( Dens.rows(1,N-1) % Backward.rows(1,N-1) ) );
      trans = trans / ( sum(trans,1) * ones(1,K) );
      
      Postprob = Forward % Backward;
      Postprob = Postprob / ( sum(Postprob,1) * ones(1,K) );
      wght = sum(Postprob,0);
      
      t_step = t_INITIAL;
      while (t_step < PRECISION ){
      // for (unsigned int i=0;i<2;i++){

        cvx = cvxObj(t_step,Postprob,wght,x,y,n,ab,F,h,N,Nrep);
        v = -solve( cvx.H,cvx.g );
        lambda = sum(v % cvx.g);
        
        s = 1;
        while(min(h - F * (vectorise(ab) + s*v)) < 0) {
          s = BETA*s; 
        }
        
        cvx_new = cvxObj(t_step,Postprob,wght,x,y,n,ab_sv(ab,s,v,K),F,h,N,Nrep);
        while (cvx_new.f > cvx.f + ALPHA*s*lambda) {
          s = BETA * s;
          cvx_new = cvxObj(t_step,Postprob,wght,x,y,n,ab_sv(ab,s,v,K),F,h,N,Nrep);
        }

        if (std::abs(lambda/2) < NTTOL) {break;}
        ab = ab_sv(ab,s,v,K);
       t_step = mu * t_step; 
      }
      
      if (std::abs( (logl(nit+1) - logl(nit)) / logl(nit+1) ) < NTTOL) {break;}
 }

out[0] = ab;
out[1] = trans;
out[2] = Postprob;
out[3] = logl;

 return out;
}