git-svn-id: http://qboxcode.org/svn/qb/trunk@592 cba15fb0-1239-40c8-b417-11db7ca47a34
 ... ... @@ -3,7 +3,7 @@ // CGIonicStepper.C // //////////////////////////////////////////////////////////////////////////////// // $Id: CGIonicStepper.C,v 1.1 2008-03-26 04:57:54 fgygi Exp$ // $Id: CGIonicStepper.C,v 1.2 2008-04-06 17:46:50 fgygi Exp$ #include "CGIonicStepper.h" #include ... ... @@ -12,41 +12,74 @@ using namespace std; //////////////////////////////////////////////////////////////////////////////// void CGIonicStepper::compute_r(double e0, const vector >& f0) { bool wolfe1; if ( first_step_ ) double fp0; bool wolfe1, wolfe2; // check if the largest component of the force f0 is larger than max_force const double max_force = 0.1; double largest_force = 0.0; for ( int is = 0; is < r0_.size(); is++ ) { wolfe1 = true; alpha_ = 1.0; for ( int i = 0; i < r0_[is].size(); i++ ) { largest_force = max(largest_force,fabs(f0[is][i])); } } else if ( largest_force > max_force ) { // Check if the first Wolfe condition is satisfied // compute predicted decrease for previous step // pred = pc_ * ( r0 - rc_ ) double pred = 0.0; if ( s_.ctxt_.onpe0() ) cout << " CGIonicStepper: force exceeds limit, taking SD step " << endl; // take a steepest descent step with limited displacement and exit const double alpha_sd = max_force/largest_force; // SD step for ( int is = 0; is < r0_.size(); is++ ) { for ( int i = 0; i < r0_[is].size(); i++ ) { pred += pc_[is][i] * ( r0_[is][i] - rc_[is][i] ); rp_[is][i] = r0_[is][i] + alpha_sd * f0[is][i]; } } const double sigma_wolfe = 0.1; wolfe1 = ( e0 < ec_ - sigma_wolfe * pred ); //cout << "CGIonicStepper: pred = " << pred << endl; //cout << "CGIonicStepper: ec: " << ec_ << endl; //cout << "CGIonicStepper: required energy: " << ec_-sigma_wolfe * pred // << " actual: " << e0 << endl; //cout << "CGIonicStepper: wolfe1 = " << wolfe1 << endl; constraints_.enforce_r(r0_,rp_); rm_ = r0_; r0_ = rp_; atoms_.set_positions(r0_); // reset the CG algorithm first_step_ = true; return; } if ( wolfe1 ) // CG algorithm if ( !first_step_ ) { // actual decrease from last step is sufficient // accept r0 as new current point rc_ = r0_; ec_ = e0; wolfe1 = e0 < ec_ + fpc_ * sigma1_ * alpha_; // fp0 = -proj(f0,pc) fp0 = 0.0; for ( int is = 0; is < r0_.size(); is++ ) { for ( int i = 0; i < r0_[is].size(); i++ ) { fp0 -= f0[is][i] * pc_[is][i]; } } wolfe2 = fabs(fp0) < sigma2_ * fabs(fpc_); if ( s_.ctxt_.onpe0() ) { cout << " CGIonicStepper: fpc = " << fpc_ << endl; cout << " CGIonicStepper: fp0 = " << fp0 << endl; cout << " CGIonicStepper: ec = " << ec_ << " e0 = " << e0 << endl; cout << " CGIonicStepper: ec_ + fpc_ * sigma1_ * alpha_ =" << ec_ + fpc_ * sigma1_ * alpha_ << endl; cout << " CGIonicStepper: wolfe1/wolfe2 = " << wolfe1 << "/" << wolfe2 << endl; } } if ( first_step_ || (wolfe1 && wolfe2) ) { // set new descent direction // pc = f0 // define new descent direction if ( first_step_ ) { ... ... @@ -66,8 +99,10 @@ void CGIonicStepper::compute_r(double e0, const vector >& f0) den += fctmp * fctmp; } } const double beta = den > 0.0 ? num/den : 0.0; //cout << "CGIonicStepper: beta = " << beta << endl; double beta = den > 0.0 ? num/den : 0.0; beta = max(beta,0.0); if ( s_.ctxt_.onpe0() ) cout << " CGIonicStepper: beta = " << beta << endl; for ( int is = 0; is < r0_.size(); is++ ) { for ( int i = 0; i < r0_[is].size(); i++ ) ... ... @@ -77,14 +112,28 @@ void CGIonicStepper::compute_r(double e0, const vector >& f0) } } fc_ = f0; alpha_ *= 1.05; } else { // backtrack alpha_ *= 0.8; // fpc = d_e / d_alpha in direction pc fpc_ = 0.0; for ( int is = 0; is < r0_.size(); is++ ) { for ( int i = 0; i < r0_[is].size(); i++ ) { fpc_ -= fc_[is][i] * pc_[is][i]; } } ec_ = e0; rc_ = r0_; fp0 = fpc_; // reset line minimizer linmin_.reset(); } //cout << "CGIonicStepper: alpha = " << alpha_ << endl; alpha_ = linmin_.newalpha(alpha_,e0,fp0); if ( s_.ctxt_.onpe0() ) cout << " CGIonicStepper: alpha = " << alpha_ << endl; // rp = rc + alpha * pc for ( int is = 0; is < r0_.size(); is++ ) { for ( int i = 0; i < r0_[is].size(); i++ ) ... ... @@ -92,6 +141,7 @@ void CGIonicStepper::compute_r(double e0, const vector >& f0) rp_[is][i] = rc_[is][i] + alpha_ * pc_[is][i]; } } constraints_.enforce_r(r0_,rp_); rm_ = r0_; r0_ = rp_; ... ...
 ... ... @@ -3,12 +3,13 @@ // CGIonicStepper.h: // //////////////////////////////////////////////////////////////////////////////// // $Id: CGIonicStepper.h,v 1.1 2008-03-26 04:57:54 fgygi Exp$ // $Id: CGIonicStepper.h,v 1.2 2008-04-06 17:46:50 fgygi Exp$ #ifndef CGIONICSTEPPER_H #define CGIONICSTEPPER_H #include "IonicStepper.h" #include "LineMinimizer.h" #include class CGIonicStepper : public IonicStepper ... ... @@ -19,12 +20,14 @@ class CGIonicStepper : public IonicStepper std::vector > rc_; std::vector > pc_; std::vector > fc_; double ec_; double alpha_; double ec_, fpc_; double alpha_, sigma1_, sigma2_; LineMinimizer linmin_; public: CGIonicStepper(Sample& s) : IonicStepper(s), first_step_(true) {} CGIonicStepper(Sample& s) : IonicStepper(s), first_step_(true), sigma1_(0.1), sigma2_(0.5) { linmin_.set_sigma1(sigma1_); } void compute_r(double e0, const std::vector >& f0); void compute_v(double e0, const std::vector >& f0) {} ... ...