double NOX::Solver::TensorBased::getNormModelResidual( const NOX::Abstract::Vector& dir, const NOX::Abstract::Group& soln, bool isTensorModel) const { // Compute residual of Newton model... Teuchos::RCP<NOX::Abstract::Vector> residualPtr = soln.getF().clone(ShapeCopy); soln.applyJacobian(dir, *residualPtr); numJvMults++; residualPtr->update(1.0, soln.getF(), 1.0); // Compute residual of Tensor model, if requested... if (isTensorModel) { double tmp = sVecPtr->innerProduct(dir); if (utilsPtr->isPrintType(NOX::Utils::Details)) utilsPtr->out() << " sc'*dt = " << utilsPtr->sciformat(tmp, 6) << std::endl; residualPtr->update(tmp*tmp, *aVecPtr, 1.0); } double modelNorm = residualPtr->norm(); return modelNorm; }
double NOX::Solver::TensorBased::getDirectionalDerivative( const NOX::Abstract::Vector& dir, const NOX::Abstract::Group& soln) const { Teuchos::RCP<NOX::Abstract::Vector> tmpPtr = soln.getF().clone(ShapeCopy); soln.applyJacobian(dir, *tmpPtr); numJvMults++; double fprime = tmpPtr->innerProduct(soln.getF()); return fprime; }
double NOX::StatusTest::NormF::computeNorm(const NOX::Abstract::Group& grp) { if (!grp.isF()) return -1.0; double norm; int n = grp.getX().length(); switch (normType) { case NOX::Abstract::Vector::TwoNorm: norm = grp.getNormF(); if (scaleType == Scaled) norm /= sqrt(1.0 * n); break; default: norm = grp.getF().norm(normType); if (scaleType == Scaled) norm /= n; break; } return norm; }
void NOX::MeritFunction::SumOfSquares:: computeGradient(const NOX::Abstract::Group& grp, NOX::Abstract::Vector& result) const { if ( !(grp.isF()) ) { utils->err() << "ERROR: NOX::MeritFunction::SumOfSquares::computeGradient() - " << "F has not been computed yet!. Please call " << "computeF() on the group passed into this function." << std::endl; throw "NOX Error"; } if ( !(grp.isJacobian()) ) { utils->err() << "ERROR: NOX::MeritFunction::SumOfSquares::computeGradient() - " << "Jacobian has not been computed yet!. Please call " << "computeJacobian() on the group passed into this function." << std::endl; throw "NOX Error"; } NOX::Abstract::Group::ReturnType status = grp.applyJacobianTranspose(grp.getF(), result); if (status != NOX::Abstract::Group::Ok) { utils->err() << "ERROR: NOX::MeritFunction::SumOfSquares::compute" << "Gradient - applyJacobianTranspose failed!" << std::endl; throw "NOX Error"; } return; }
double NOX::MeritFunction::SumOfSquares:: computeSlopeWithoutJacobian(const NOX::Abstract::Vector& dir, const NOX::Abstract::Group& grp) const { if (Teuchos::is_null(tmpVecPtr)) tmpVecPtr = grp.getF().clone(NOX::ShapeCopy); if (Teuchos::is_null(tmpGrpPtr)) tmpGrpPtr = grp.clone(NOX::ShapeCopy); // Compute the perturbation parameter double lambda = 1.0e-6; double denominator = dir.norm(); // Don't divide by zero if (denominator == 0.0) denominator = 1.0; double eta = lambda * (lambda + grp.getX().norm() / denominator); // Don't divide by zero if (eta == 0.0) eta = 1.0e-6; // Perturb the solution vector tmpVecPtr->update(eta, dir, 1.0, grp.getX(), 0.0); // Compute the new F --> F(x + eta * dir) tmpGrpPtr->setX(*(tmpVecPtr.get())); tmpGrpPtr->computeF(); // Compute Js = (F(x + eta * dir) - F(x))/eta tmpVecPtr->update(-1.0/eta, grp.getF(), 1.0/eta, tmpGrpPtr->getF(), 0.0); return(tmpVecPtr->innerProduct(grp.getF())); }
void NOX::MeritFunction::SumOfSquares:: computeQuadraticMinimizer(const NOX::Abstract::Group& grp, NOX::Abstract::Vector& result) const { // Clone a temporary vector if (Teuchos::is_null(tmpVecPtr)) tmpVecPtr = grp.getF().clone(NOX::ShapeCopy); // Make sure the function and Jacobian have been evaluated if ( !(grp.isF()) ) { utils->err() << "ERROR: NOX::MeritFunction::SumOfSquares::" << "computeQuadraticMinimizer() - " << "F has not been computed yet!. Please call " << "computeF() on the group passed into this function." << std::endl; throw "NOX Error"; } if ( !(grp.isJacobian()) ) { utils->err() << "ERROR: NOX::MeritFunction::SumOfSquares::" << "computeQuadraticMinimizer() - " << "Jacobian has not been computed yet!. Please call " << "computeJacobian() on the group passed into this function." << std::endl; throw "NOX Error"; } // Compute the steepest descent direction = J^T F this->computeGradient(grp, result); // Compute = J (J^T F) NOX::Abstract::Group::ReturnType status = grp.applyJacobian(result, *tmpVecPtr); if (status != NOX::Abstract::Group::Ok) { utils->err() << "ERROR: NOX::MeritFunction::SumOfSquares::" << "computeQuadraticMinimizer() - grp->applyJacobian() has failed!" << std::endl; throw "NOX Error"; } result.scale( -1.0 * result.innerProduct(result) / tmpVecPtr->innerProduct(*tmpVecPtr) ); }
double NOX::MeritFunction::SumOfSquares:: computeQuadraticModel(const NOX::Abstract::Vector& dir, const NOX::Abstract::Group& grp) const { if (Teuchos::is_null(tmpVecPtr)) tmpVecPtr = grp.getF().clone(); double m = 0.0; m = this->computef(grp); m += this->computeSlope(dir, grp); grp.applyJacobian(dir, *(tmpVecPtr.get())); m += 0.5 * tmpVecPtr->innerProduct(*(tmpVecPtr.get())); return m; }
double NOX::MeritFunction::SumOfSquares:: computeSlope(const NOX::Abstract::Vector& dir, const NOX::Abstract::Group& grp) const { if (Teuchos::is_null(tmpVecPtr)) tmpVecPtr = grp.getF().clone(); // If the Jacobian is not computed, approximate it with // directional derivatives. dir^T J^T F = F^T Jd if (!(grp.isJacobian())) return this->computeSlopeWithoutJacobian(dir, grp); // If the Jacobian is computed but doesn't support a gradient, // employ a different form for the inner product, eg // return <v, F> = F' * J * dir = <J'F, dir> = <g, dir> else if(!(grp.isGradient())) return this->computeSlopeWithoutJacobianTranspose(dir, grp); this->computeGradient(grp, *(tmpVecPtr.get())); return dir.innerProduct(*(tmpVecPtr.get())); }
// ************************************************************************** // *** computeForcingTerm // ************************************************************************** double NOX::Direction::Utils::InexactNewton:: computeForcingTerm(const NOX::Abstract::Group& soln, const NOX::Abstract::Group& oldsoln, int niter, const NOX::Solver::Generic& solver, double eta_last) { const std::string indent = " "; if (forcingTermMethod == Constant) { if (printing->isPrintType(NOX::Utils::Details)) { printing->out() << indent << "CALCULATING FORCING TERM" << std::endl; printing->out() << indent << "Method: Constant" << std::endl; printing->out() << indent << "Forcing Term: " << eta_k << std::endl; } if (setTolerance) paramsPtr->sublist(directionMethod).sublist("Linear Solver"). set("Tolerance", eta_k); return eta_k; } // Get linear solver current tolerance. // NOTE: These values are changing at each nonlinear iteration and // must either be updated from the parameter list each time a compute // is called or supplied during the function call! double eta_km1 = 0.0; if (eta_last < 0.0) eta_km1 = paramsPtr->sublist(directionMethod). sublist("Linear Solver").get("Tolerance", 0.0); else eta_km1 = eta_last; // Tolerance may have been adjusted in a line search algorithm so we // have to account for this. const NOX::Solver::LineSearchBased* solverPtr = 0; solverPtr = dynamic_cast<const NOX::Solver::LineSearchBased*>(&solver); if (solverPtr != 0) { eta_km1 = 1.0 - solverPtr->getStepSize() * (1.0 - eta_km1); } if (printing->isPrintType(NOX::Utils::Details)) { printing->out() << indent << "CALCULATING FORCING TERM" << std::endl; printing->out() << indent << "Method: " << method << std::endl; } if (forcingTermMethod == Type1) { if (niter == 0) { eta_k = eta_initial; } else { // Return norm of predicted F // do NOT use the following lines!! This does NOT account for // line search step length taken. // const double normpredf = 0.0; // oldsoln.getNormLastLinearSolveResidual(normpredf); // Create a new vector to be the predicted RHS if (Teuchos::is_null(predRhs)) { predRhs = oldsoln.getF().clone(ShapeCopy); } if (Teuchos::is_null(stepDir)) { stepDir = oldsoln.getF().clone(ShapeCopy); } // stepDir = X - oldX (i.e., the step times the direction) stepDir->update(1.0, soln.getX(), -1.0, oldsoln.getX(), 0); // Compute predRhs = Jacobian * step * dir if (!(oldsoln.isJacobian())) { if (printing->isPrintType(NOX::Utils::Details)) { printing->out() << "WARNING: NOX::InexactNewtonUtils::resetForcingTerm() - " << "Jacobian is out of date! Recomputing Jacobian." << std::endl; } const_cast<NOX::Abstract::Group&>(oldsoln).computeJacobian(); } oldsoln.applyJacobian(*stepDir, *predRhs); // Compute predRhs = RHSVector + predRhs (this is the predicted RHS) predRhs->update(1.0, oldsoln.getF(), 1.0); // Compute the norms double normpredf = predRhs->norm(); double normf = soln.getNormF(); double normoldf = oldsoln.getNormF(); if (printing->isPrintType(NOX::Utils::Details)) { printing->out() << indent << "Forcing Term Norm: Using L-2 Norm." << std::endl; } // Compute forcing term eta_k = fabs(normf - normpredf) / normoldf; // Some output if (printing->isPrintType(NOX::Utils::Details)) { printing->out() << indent << "Residual Norm k-1 = " << normoldf << "\n"; printing->out() << indent << "Residual Norm Linear Model k = " << normpredf << "\n"; printing->out() << indent << "Residual Norm k = " << normf << "\n"; printing->out() << indent << "Calculated eta_k (pre-bounds) = " << eta_k << std::endl; } // Impose safeguard and constraints ... const double tmp = (1.0 + sqrt(5.0)) / 2.0; const double eta_km1_alpha = pow(eta_km1, tmp); if (eta_km1_alpha > 0.1) eta_k = NOX_MAX(eta_k, eta_km1_alpha); eta_k = NOX_MAX(eta_k, eta_min); eta_k = NOX_MIN(eta_max, eta_k); } } else if (forcingTermMethod == Type2) { if (niter == 0) { eta_k = eta_initial; } else { double normf = soln.getNormF(); double normoldf = oldsoln.getNormF(); if (printing->isPrintType(NOX::Utils::Details)) { printing->out() << indent << "Forcing Term Norm: Using L-2 Norm." << std::endl; } const double residual_ratio = normf / normoldf; eta_k = gamma * pow(residual_ratio, alpha); // Some output if (printing->isPrintType(NOX::Utils::Details)) { printing->out() << indent << "Residual Norm k-1 = " << normoldf << "\n"; printing->out() << indent << "Residual Norm k = " << normf << "\n"; printing->out() << indent << "Calculated eta_k (pre-bounds) = " << eta_k << std::endl; } // Impose safeguard and constraints ... const double eta_k_alpha = gamma * pow(eta_km1, alpha); if (eta_k_alpha > 0.1) eta_k = NOX_MAX(eta_k, eta_k_alpha); eta_k = NOX_MAX(eta_k, eta_min); eta_k = NOX_MIN(eta_max, eta_k); } } // Set the new linear solver tolerance if (setTolerance) paramsPtr->sublist(directionMethod).sublist("Linear Solver"). set("Tolerance", eta_k); if (printing->isPrintType(NOX::Utils::Details)) printing->out() << indent << "Forcing Term: " << eta_k << std::endl; return eta_k; }
bool NOX::Direction::ModifiedNewton:: compute(NOX::Abstract::Vector& dir, NOX::Abstract::Group& soln, const NOX::Solver::Generic& solver) { NOX::Abstract::Group::ReturnType status; // Compute F at current solution status = soln.computeF(); if (status != NOX::Abstract::Group::Ok) throwError("compute", "Unable to compute F"); maxAgeOfJacobian = paramsPtr->sublist("Modified-Newton").get("Max Age of Jacobian", 10); if (Teuchos::is_null(oldJacobianGrpPtr)) { oldJacobianGrpPtr = soln.clone(DeepCopy); } NOX::Abstract::Group& oldJacobianGrp = *oldJacobianGrpPtr; status = NOX::Abstract::Group::Failed; while (status != NOX::Abstract::Group::Ok) { // Conditionally compute Jacobian at current solution. if ( (ageOfJacobian == -1) || (ageOfJacobian == maxAgeOfJacobian) ) { if (ageOfJacobian > 0) oldJacobianGrp = soln; status = oldJacobianGrp.computeJacobian(); if (status != NOX::Abstract::Group::Ok) throwError("compute", "Unable to compute Jacobian"); ageOfJacobian = 1; } else ageOfJacobian++; // Compute the Modified Newton direction status = oldJacobianGrp.applyJacobianInverse(paramsPtr->sublist("Modified-Newton").sublist("Linear Solver"), soln.getF(), dir); dir.scale(-1.0); // It didn't converge, but maybe we can recover. if ((status != NOX::Abstract::Group::Ok) && (doRescue == false)) { throwError("compute", "Unable to solve Newton system"); } else if ((status != NOX::Abstract::Group::Ok) && (doRescue == true)) { if (utils->isPrintType(NOX::Utils::Warning)) utils->out() << "WARNING: NOX::Direction::ModifiedNewton::compute() - " << "Linear solve failed to achieve convergence - " << "using the step anyway since \"Rescue Bad Newton Solve\" " << "is true. Also, flagging recompute of Jacobian." << std::endl; ageOfJacobian = maxAgeOfJacobian; status = NOX::Abstract::Group::Ok; } } return true; }
bool NOX::Solver::TensorBased::computeTensorDirection(NOX::Abstract::Group& soln, const NOX::Solver::Generic& solver) { NOX::Abstract::Group::ReturnType dir_status; Teuchos::ParameterList& linearParams = paramsPtr->sublist("Direction"). sublist(paramsPtr->sublist("Direction"). get("Method","Tensor")). sublist("Linear Solver"); // Compute F at current solution. dir_status = soln.computeF(); if (dir_status != NOX::Abstract::Group::Ok) throwError("computeTensorDirection", "Unable to compute F"); // Compute Jacobian at current solution. dir_status = soln.computeJacobian(); if (dir_status != NOX::Abstract::Group::Ok) throwError("computeTensorDirection", "Unable to compute Jacobian"); // Begin processing for the tensor step, if necessary. double sDotS = 0.0; int tempVal1 = 0; if ((nIter > 0) && (requestedBaseStep == TensorStep)) { // Compute the tensor term s = x_{k-1} - x_k *sVecPtr = soln.getX(); sVecPtr->update(1.0, solver.getPreviousSolutionGroup().getX(), -1.0); double normS = sVecPtr->norm(); sDotS = normS * normS; // Form the tensor term a = (F_{k-1} - F_k - J*s) / (s^T s)^2 soln.applyJacobian(*sVecPtr, *aVecPtr); numJvMults++; aVecPtr->update(1.0, solver.getPreviousSolutionGroup().getF(), -1.0); aVecPtr->update(-1.0, soln.getF(), 1.0); if (sDotS != 0) aVecPtr->scale(1.0 / (sDotS * sDotS)); // Save old Newton step as initial guess to second system *tmpVecPtr = *newtonVecPtr; tmpVecPtr->scale(-1.0); // Rewrite to avoid this? // Compute residual of linear system using initial guess... soln.applyJacobian(*tmpVecPtr, *residualVecPtr); numJvMults++; residualVecPtr->update(1.0, solver.getPreviousSolutionGroup().getF(),-1.0); double residualNorm = residualVecPtr->norm(); #if DEBUG_LEVEL > 0 double tmpVecNorm = tmpVecPtr->norm(); double residualNormRel = residualNorm / solver.getPreviousSolutionGroup().getNormF(); if (utilsPtr->isPrintType(NOX::Utils::Details)) { utilsPtr->out() << " Norm of initial guess: " << utilsPtr->sciformat(tmpVecNorm, 6) << std::endl; utilsPtr->out() << " initg norm of model residual = " << utilsPtr->sciformat(residualNorm, 6) << " (abs) " << utilsPtr->sciformat(residualNormRel, 6) << " (rel)" << std::endl; } #endif // Save some parameters and use them later... double tol = linearParams.get("Tolerance", 1e-4); double relativeResidual = residualNorm / solver.getPreviousSolutionGroup().getNormF(); // Decide whether to use initial guess... bool isInitialGuessGood = false; #ifdef USE_INITIAL_GUESS_LOGIC if (relativeResidual < 1.0) { if (utilsPtr->isPrintType(NOX::Utils::Details)) utilsPtr->out() << " Initial guess is good..." << std::endl; isInitialGuessGood = true; // RPP - Brett please make sure the line below is correct. *tensorVecPtr = *tmpVecPtr; double newTol = tol / relativeResidual; if (newTol > 0.99) newTol = 0.99; // force at least one iteration linearParams.set("Tolerance", newTol); if (utilsPtr->isPrintType(NOX::Utils::Details)) utilsPtr->out() << " Setting tolerance to " << utilsPtr->sciformat(newTol,6) << std::endl; } else #endif // USE_INITIAL_GUESS_LOGIC { //utilsPtr->out() << " Initial guess is BAD... do not use!\n"; isInitialGuessGood = false; *residualVecPtr = solver.getPreviousSolutionGroup().getF(); } // Compute the term inv(J)*Fp.... tmpVecPtr->init(0.0); dir_status = soln.applyJacobianInverse(linearParams, *residualVecPtr, *tmpVecPtr); // If it didn't converge, maybe we can recover. if (dir_status != NOX::Abstract::Group::Ok) { if (doRescue == false) throwError("computeTensorDirection", "Unable to apply Jacobian inverse"); else if ((doRescue == true) && (utilsPtr->isPrintType(NOX::Utils::Warning))) utilsPtr->out() << "WARNING: NOX::Solver::TensorBased::computeTensorDirection() - " << "Linear solve failed to achieve convergence - " << "using the step anyway " << "since \"Rescue Bad Newton Solve\" is true." << std::endl; } // Continue processing #ifdef USE_INITIAL_GUESS_LOGIC if (isInitialGuessGood) { tmpVecPtr->update(1.0, *tensorVecPtr, 1.0); linearParams.set("Tolerance", tol); } #endif // Save iteration count for comparison later if (linearParams.sublist("Output"). isParameter("Number of Linear Iterations")) tempVal1 = linearParams.sublist("Output"). get("Number of Linear Iterations",0); #if DEBUG_LEVEL > 0 // Compute residual of linear system with initial guess... soln.applyJacobian(*tmpVecPtr, *residualVecPtr); numJvMults++; residualVec.update(-1.0, solver.getPreviousSolutionGroup().getF(),1.0); double residualNorm2 = residualVec.norm(); double residualNorm2Rel = residualNorm2 / solver.getPreviousSolutionGroup().getNormF(); if (utilsPtr->isPrintType(NOX::Utils::Details)) utilsPtr->out() << " jifp norm of model residual = " << utilsPtr->sciformat(residualNorm2, 6) << " (abs) " << utilsPtr->sciformat(residualNorm2Rel, 6) << " (rel)" << std::endl; #endif } // Compute the Newton direction dir_status = soln.computeNewton(linearParams); // If it didn't converge, maybe we can recover. if (dir_status != NOX::Abstract::Group::Ok) { if (doRescue == false) throwError("computeTensorDirection", "Unable to apply Jacobian inverse"); else if ((doRescue == true) && (utilsPtr->isPrintType(NOX::Utils::Warning))) utilsPtr->out() << "WARNING: NOX::Solver::TensorBased::computeTensorDirection() - " << "Linear solve failed to achieve convergence - " << "using the step anyway " << "since \"Rescue Bad Newton Solve\" is true." << std::endl; } // Set Newton direction *newtonVecPtr = soln.getNewton(); // Update counter int tempVal2 = 0; if (linearParams.sublist("Output"). isParameter("Number of Linear Iterations")) tempVal2 = linearParams.sublist("Output"). get("Number of Linear Iterations",0); numJ2vMults += (tempVal1 > tempVal2) ? tempVal1 : tempVal2; #ifdef CHECK_RESIDUALS printDirectionInfo("newtonVec", *newtonVecPtr, soln, false); #endif // CHECK_RESIDUALS // Continue processing the tensor step, if necessary if ((nIter > 0) && (requestedBaseStep == TensorStep)) { // Form the term inv(J)*a... (note that a is not multiplied by 2) // The next line does not work in some implementations for some reason //tmpVec.update(1.0, newtonVec, -1.0, sVec, 1.0); tmpVecPtr->update(1.0, *newtonVecPtr, 1.0); tmpVecPtr->update(-1.0, *sVecPtr, 1.0); if (sDotS != 0.0) tmpVecPtr->scale( 1.0 / (sDotS * sDotS)); // Calculate value of beta sTinvJF = -sVecPtr->innerProduct(*newtonVecPtr); sTinvJa = sVecPtr->innerProduct(*tmpVecPtr); double qval = 0; double lambdaBar = 1; beta = calculateBeta(sTinvJa, 1.0, sTinvJF, qval, lambdaBar); double sVecNorm = sVecPtr->norm(); double aVecNorm = aVecPtr->norm(); if (utilsPtr->isPrintType(NOX::Utils::Details)) { utilsPtr->out() << " sTinvJF = " << utilsPtr->sciformat(sTinvJF, 6) << " sTinvJa = " << utilsPtr->sciformat(sTinvJa, 6) << std::endl; utilsPtr->out() << " norm(s) = " << utilsPtr->sciformat(sVecNorm, 6) << " norm(a) = " << utilsPtr->sciformat(aVecNorm, 6) << std::endl; } if (useModifiedMethod) { double alpha2 = lambdaBar; if (utilsPtr->isPrintType(NOX::Utils::Details)) utilsPtr->out() << " Beta = " << utilsPtr->sciformat(beta, 6) << " Alpha2 = " << utilsPtr->sciformat(alpha2, 6) << std::endl; if (alpha2 != 1.0) { if (utilsPtr->isPrintType(NOX::Utils::Details)) utilsPtr->out() << " *** Scaling tensor term a ***" << std::endl; aVecPtr->scale(alpha2); tmpVecPtr->scale(alpha2); sTinvJa *= alpha2; beta /= alpha2; lambdaBar = 1.0; qval = 0; } } // Form the tensor step tensorVecPtr->update(1.0, *newtonVecPtr, -beta*beta, *tmpVecPtr, 0.0); #ifdef CHECK_RESIDUALS printDirectionInfo("tensorVec", *tensorVecPtr, soln, true); #endif // CHECK_RESIDUALS #if DEBUG_LEVEL > 0 double sDotT = tensorVecPtr->innerProduct(sVec); if (utilsPtr->isPrintType(NOX::Utils::Details)) utilsPtr->out() << " Beta = " << utilsPtr->sciformat(beta, 6) << " std = " << utilsPtr->sciformat(sDotT, 6) << " qval = " << utilsPtr->sciformat(qval, 2) << " lambdaBar = " << lambdaBar << std::endl; #endif } else *tensorVecPtr = *newtonVecPtr; return true; }
bool NOX::Direction::Broyden::compute(NOX::Abstract::Vector& dir, NOX::Abstract::Group& soln, const NOX::Solver::LineSearchBased& solver) { // Return value for group operations (temp variable) NOX::Abstract::Group::ReturnType status; // Compute F at current solution status = soln.computeF(); if (status != NOX::Abstract::Group::Ok) throwError("compute", "Unable to compute F"); // Check for restart if (doRestart(soln, solver)) { // Reset memory memory.reset(); // Update group if (Teuchos::is_null(oldJacobianGrpPtr)) oldJacobianGrpPtr = soln.clone(NOX::DeepCopy); else // RPP - update the entire group (this grabs state vectors in xyce). // Otherwise, xyce is forced to recalculate F at each iteration. //oldJacobianGrpPtr->setX(soln.getX()); *oldJacobianGrpPtr = soln; // Calcuate new Jacobian if (utils->isPrintType(NOX::Utils::Details)) utils->out() << " Recomputing Jacobian" << endl; status = oldJacobianGrpPtr->computeJacobian(); if (status != NOX::Abstract::Group::Ok) throwError("compute", "Unable to compute Jacobian"); // Reset counter cnt = 0; } // If necesary, scale the s-vector from the last iteration if (!memory.empty()) { double step = solver.getStepSize(); memory[memory.size() - 1].setStep(step); } // --- Calculate the Broyden direction --- // Compute inexact forcing term if requested. inexactNewtonUtils.computeForcingTerm(soln, solver.getPreviousSolutionGroup(), solver.getNumIterations(), solver); // dir = - J_old^{-1} * F cnt ++; status = oldJacobianGrpPtr->applyJacobianInverse(*lsParamsPtr, soln.getF(), dir); if (status != NOX::Abstract::Group::Ok) throwError("compute", "Unable to apply Jacobian inverse"); dir.scale(-1.0); // Apply the Broyden modifications to the old Jacobian (implicitly) if (!memory.empty()) { // Number of elements in the memory int m = memory.size(); // Information corresponding to index i double step; Teuchos::RCP<const NOX::Abstract::Vector> sPtr; // Information corresponding to index i + 1 // (initialized for i = -1) double stepNext = memory[0].step(); Teuchos::RCP<const NOX::Abstract::Vector> sPtrNext = memory[0].sPtr(); // Intermediate storage double a, b, c, denom; for (int i = 0; i < m-1; i ++) { step = stepNext; sPtr = sPtrNext; stepNext = memory[i+1].step(); sPtrNext = memory[i+1].sPtr(); a = step / stepNext; b = step - 1; c = sPtr->innerProduct(dir) / memory[i].sNormSqr(); dir.update(a * c, *sPtrNext, b * c, *sPtr, 1.0); } step = stepNext; sPtr = sPtrNext; a = sPtr->innerProduct(dir); // <s,z> b = memory[m-1].sNormSqr(); // ||s||^2 c = (step - 1) * a; // (\lambda-1) <s,z> denom = b - step * a; // ||s||^2 - \lambda <s,z> dir.update(c / denom, *sPtr, b / denom); } //! Add this direction to the memory memory.push(dir); return true; }