|  | // -*- coding: utf-8 | 
|  | // vim: set fileencoding=utf-8 | 
|  |  | 
|  | // This file is part of Eigen, a lightweight C++ template library | 
|  | // for linear algebra. | 
|  | // | 
|  | // Copyright (C) 2009 Thomas Capricelli <orzel@freehackers.org> | 
|  | // | 
|  | // This Source Code Form is subject to the terms of the Mozilla | 
|  | // Public License v. 2.0. If a copy of the MPL was not distributed | 
|  | // with this file, You can obtain one at http://mozilla.org/MPL/2.0/. | 
|  |  | 
|  | #ifndef EIGEN_LEVENBERGMARQUARDT__H | 
|  | #define EIGEN_LEVENBERGMARQUARDT__H | 
|  |  | 
|  | #include "./InternalHeaderCheck.h" | 
|  |  | 
|  | namespace Eigen { | 
|  |  | 
|  | namespace LevenbergMarquardtSpace { | 
|  | enum Status { | 
|  | NotStarted = -2, | 
|  | Running = -1, | 
|  | ImproperInputParameters = 0, | 
|  | RelativeReductionTooSmall = 1, | 
|  | RelativeErrorTooSmall = 2, | 
|  | RelativeErrorAndReductionTooSmall = 3, | 
|  | CosinusTooSmall = 4, | 
|  | TooManyFunctionEvaluation = 5, | 
|  | FtolTooSmall = 6, | 
|  | XtolTooSmall = 7, | 
|  | GtolTooSmall = 8, | 
|  | UserAsked = 9 | 
|  | }; | 
|  | } | 
|  |  | 
|  |  | 
|  |  | 
|  | /** | 
|  | * \ingroup NonLinearOptimization_Module | 
|  | * \brief Performs non linear optimization over a non-linear function, | 
|  | * using a variant of the Levenberg Marquardt algorithm. | 
|  | * | 
|  | * Check wikipedia for more information. | 
|  | * http://en.wikipedia.org/wiki/Levenberg%E2%80%93Marquardt_algorithm | 
|  | */ | 
|  | template<typename FunctorType, typename Scalar=double> | 
|  | class LevenbergMarquardt | 
|  | { | 
|  | static Scalar sqrt_epsilon() | 
|  | { | 
|  | using std::sqrt; | 
|  | return sqrt(NumTraits<Scalar>::epsilon()); | 
|  | } | 
|  |  | 
|  | public: | 
|  | LevenbergMarquardt(FunctorType &_functor) | 
|  | : functor(_functor) { nfev = njev = iter = 0;  fnorm = gnorm = 0.; useExternalScaling=false; } | 
|  |  | 
|  | typedef DenseIndex Index; | 
|  |  | 
|  | struct Parameters { | 
|  | Parameters() | 
|  | : factor(Scalar(100.)) | 
|  | , maxfev(400) | 
|  | , ftol(sqrt_epsilon()) | 
|  | , xtol(sqrt_epsilon()) | 
|  | , gtol(Scalar(0.)) | 
|  | , epsfcn(Scalar(0.)) {} | 
|  | Scalar factor; | 
|  | Index maxfev;   // maximum number of function evaluation | 
|  | Scalar ftol; | 
|  | Scalar xtol; | 
|  | Scalar gtol; | 
|  | Scalar epsfcn; | 
|  | }; | 
|  |  | 
|  | typedef Matrix< Scalar, Dynamic, 1 > FVectorType; | 
|  | typedef Matrix< Scalar, Dynamic, Dynamic > JacobianType; | 
|  |  | 
|  | LevenbergMarquardtSpace::Status lmder1( | 
|  | FVectorType &x, | 
|  | const Scalar tol = sqrt_epsilon() | 
|  | ); | 
|  |  | 
|  | LevenbergMarquardtSpace::Status minimize(FVectorType &x); | 
|  | LevenbergMarquardtSpace::Status minimizeInit(FVectorType &x); | 
|  | LevenbergMarquardtSpace::Status minimizeOneStep(FVectorType &x); | 
|  |  | 
|  | static LevenbergMarquardtSpace::Status lmdif1( | 
|  | FunctorType &functor, | 
|  | FVectorType &x, | 
|  | Index *nfev, | 
|  | const Scalar tol = sqrt_epsilon() | 
|  | ); | 
|  |  | 
|  | LevenbergMarquardtSpace::Status lmstr1( | 
|  | FVectorType  &x, | 
|  | const Scalar tol = sqrt_epsilon() | 
|  | ); | 
|  |  | 
|  | LevenbergMarquardtSpace::Status minimizeOptimumStorage(FVectorType  &x); | 
|  | LevenbergMarquardtSpace::Status minimizeOptimumStorageInit(FVectorType  &x); | 
|  | LevenbergMarquardtSpace::Status minimizeOptimumStorageOneStep(FVectorType  &x); | 
|  |  | 
|  | void resetParameters(void) { parameters = Parameters(); } | 
|  |  | 
|  | Parameters parameters; | 
|  | FVectorType  fvec, qtf, diag; | 
|  | JacobianType fjac; | 
|  | PermutationMatrix<Dynamic,Dynamic> permutation; | 
|  | Index nfev; | 
|  | Index njev; | 
|  | Index iter; | 
|  | Scalar fnorm, gnorm; | 
|  | bool useExternalScaling; | 
|  |  | 
|  | Scalar lm_param(void) { return par; } | 
|  | private: | 
|  |  | 
|  | FunctorType &functor; | 
|  | Index n; | 
|  | Index m; | 
|  | FVectorType wa1, wa2, wa3, wa4; | 
|  |  | 
|  | Scalar par, sum; | 
|  | Scalar temp, temp1, temp2; | 
|  | Scalar delta; | 
|  | Scalar ratio; | 
|  | Scalar pnorm, xnorm, fnorm1, actred, dirder, prered; | 
|  |  | 
|  | LevenbergMarquardt& operator=(const LevenbergMarquardt&); | 
|  | }; | 
|  |  | 
|  | template<typename FunctorType, typename Scalar> | 
|  | LevenbergMarquardtSpace::Status | 
|  | LevenbergMarquardt<FunctorType,Scalar>::lmder1( | 
|  | FVectorType  &x, | 
|  | const Scalar tol | 
|  | ) | 
|  | { | 
|  | n = x.size(); | 
|  | m = functor.values(); | 
|  |  | 
|  | /* check the input parameters for errors. */ | 
|  | if (n <= 0 || m < n || tol < 0.) | 
|  | return LevenbergMarquardtSpace::ImproperInputParameters; | 
|  |  | 
|  | resetParameters(); | 
|  | parameters.ftol = tol; | 
|  | parameters.xtol = tol; | 
|  | parameters.maxfev = 100*(n+1); | 
|  |  | 
|  | return minimize(x); | 
|  | } | 
|  |  | 
|  |  | 
|  | template<typename FunctorType, typename Scalar> | 
|  | LevenbergMarquardtSpace::Status | 
|  | LevenbergMarquardt<FunctorType,Scalar>::minimize(FVectorType  &x) | 
|  | { | 
|  | LevenbergMarquardtSpace::Status status = minimizeInit(x); | 
|  | if (status==LevenbergMarquardtSpace::ImproperInputParameters) | 
|  | return status; | 
|  | do { | 
|  | status = minimizeOneStep(x); | 
|  | } while (status==LevenbergMarquardtSpace::Running); | 
|  | return status; | 
|  | } | 
|  |  | 
|  | template<typename FunctorType, typename Scalar> | 
|  | LevenbergMarquardtSpace::Status | 
|  | LevenbergMarquardt<FunctorType,Scalar>::minimizeInit(FVectorType  &x) | 
|  | { | 
|  | n = x.size(); | 
|  | m = functor.values(); | 
|  |  | 
|  | wa1.resize(n); wa2.resize(n); wa3.resize(n); | 
|  | wa4.resize(m); | 
|  | fvec.resize(m); | 
|  | fjac.resize(m, n); | 
|  | if (!useExternalScaling) | 
|  | diag.resize(n); | 
|  | eigen_assert( (!useExternalScaling || diag.size()==n) && "When useExternalScaling is set, the caller must provide a valid 'diag'"); | 
|  | qtf.resize(n); | 
|  |  | 
|  | /* Function Body */ | 
|  | nfev = 0; | 
|  | njev = 0; | 
|  |  | 
|  | /*     check the input parameters for errors. */ | 
|  | if (n <= 0 || m < n || parameters.ftol < 0. || parameters.xtol < 0. || parameters.gtol < 0. || parameters.maxfev <= 0 || parameters.factor <= 0.) | 
|  | return LevenbergMarquardtSpace::ImproperInputParameters; | 
|  |  | 
|  | if (useExternalScaling) | 
|  | for (Index j = 0; j < n; ++j) | 
|  | if (diag[j] <= 0.) | 
|  | return LevenbergMarquardtSpace::ImproperInputParameters; | 
|  |  | 
|  | /*     evaluate the function at the starting point */ | 
|  | /*     and calculate its norm. */ | 
|  | nfev = 1; | 
|  | if ( functor(x, fvec) < 0) | 
|  | return LevenbergMarquardtSpace::UserAsked; | 
|  | fnorm = fvec.stableNorm(); | 
|  |  | 
|  | /*     initialize levenberg-marquardt parameter and iteration counter. */ | 
|  | par = 0.; | 
|  | iter = 1; | 
|  |  | 
|  | return LevenbergMarquardtSpace::NotStarted; | 
|  | } | 
|  |  | 
|  | template<typename FunctorType, typename Scalar> | 
|  | LevenbergMarquardtSpace::Status | 
|  | LevenbergMarquardt<FunctorType,Scalar>::minimizeOneStep(FVectorType  &x) | 
|  | { | 
|  | using std::abs; | 
|  | using std::sqrt; | 
|  |  | 
|  | eigen_assert(x.size()==n); // check the caller is not cheating us | 
|  |  | 
|  | /* calculate the jacobian matrix. */ | 
|  | Index df_ret = functor.df(x, fjac); | 
|  | if (df_ret<0) | 
|  | return LevenbergMarquardtSpace::UserAsked; | 
|  | if (df_ret>0) | 
|  | // numerical diff, we evaluated the function df_ret times | 
|  | nfev += df_ret; | 
|  | else njev++; | 
|  |  | 
|  | /* compute the qr factorization of the jacobian. */ | 
|  | wa2 = fjac.colwise().blueNorm(); | 
|  | ColPivHouseholderQR<JacobianType> qrfac(fjac); | 
|  | fjac = qrfac.matrixQR(); | 
|  | permutation = qrfac.colsPermutation(); | 
|  |  | 
|  | /* on the first iteration and if external scaling is not used, scale according */ | 
|  | /* to the norms of the columns of the initial jacobian. */ | 
|  | if (iter == 1) { | 
|  | if (!useExternalScaling) | 
|  | for (Index j = 0; j < n; ++j) | 
|  | diag[j] = (wa2[j]==0.)? 1. : wa2[j]; | 
|  |  | 
|  | /* on the first iteration, calculate the norm of the scaled x */ | 
|  | /* and initialize the step bound delta. */ | 
|  | xnorm = diag.cwiseProduct(x).stableNorm(); | 
|  | delta = parameters.factor * xnorm; | 
|  | if (delta == 0.) | 
|  | delta = parameters.factor; | 
|  | } | 
|  |  | 
|  | /* form (q transpose)*fvec and store the first n components in */ | 
|  | /* qtf. */ | 
|  | wa4 = fvec; | 
|  | wa4.applyOnTheLeft(qrfac.householderQ().adjoint()); | 
|  | qtf = wa4.head(n); | 
|  |  | 
|  | /* compute the norm of the scaled gradient. */ | 
|  | gnorm = 0.; | 
|  | if (fnorm != 0.) | 
|  | for (Index j = 0; j < n; ++j) | 
|  | if (wa2[permutation.indices()[j]] != 0.) | 
|  | gnorm = (std::max)(gnorm, abs( fjac.col(j).head(j+1).dot(qtf.head(j+1)/fnorm) / wa2[permutation.indices()[j]])); | 
|  |  | 
|  | /* test for convergence of the gradient norm. */ | 
|  | if (gnorm <= parameters.gtol) | 
|  | return LevenbergMarquardtSpace::CosinusTooSmall; | 
|  |  | 
|  | /* rescale if necessary. */ | 
|  | if (!useExternalScaling) | 
|  | diag = diag.cwiseMax(wa2); | 
|  |  | 
|  | do { | 
|  |  | 
|  | /* determine the levenberg-marquardt parameter. */ | 
|  | internal::lmpar2<Scalar>(qrfac, diag, qtf, delta, par, wa1); | 
|  |  | 
|  | /* store the direction p and x + p. calculate the norm of p. */ | 
|  | wa1 = -wa1; | 
|  | wa2 = x + wa1; | 
|  | pnorm = diag.cwiseProduct(wa1).stableNorm(); | 
|  |  | 
|  | /* on the first iteration, adjust the initial step bound. */ | 
|  | if (iter == 1) | 
|  | delta = (std::min)(delta,pnorm); | 
|  |  | 
|  | /* evaluate the function at x + p and calculate its norm. */ | 
|  | if ( functor(wa2, wa4) < 0) | 
|  | return LevenbergMarquardtSpace::UserAsked; | 
|  | ++nfev; | 
|  | fnorm1 = wa4.stableNorm(); | 
|  |  | 
|  | /* compute the scaled actual reduction. */ | 
|  | actred = -1.; | 
|  | if (Scalar(.1) * fnorm1 < fnorm) | 
|  | actred = 1. - numext::abs2(fnorm1 / fnorm); | 
|  |  | 
|  | /* compute the scaled predicted reduction and */ | 
|  | /* the scaled directional derivative. */ | 
|  | wa3 = fjac.template triangularView<Upper>() * (qrfac.colsPermutation().inverse() *wa1); | 
|  | temp1 = numext::abs2(wa3.stableNorm() / fnorm); | 
|  | temp2 = numext::abs2(sqrt(par) * pnorm / fnorm); | 
|  | prered = temp1 + temp2 / Scalar(.5); | 
|  | dirder = -(temp1 + temp2); | 
|  |  | 
|  | /* compute the ratio of the actual to the predicted */ | 
|  | /* reduction. */ | 
|  | ratio = 0.; | 
|  | if (prered != 0.) | 
|  | ratio = actred / prered; | 
|  |  | 
|  | /* update the step bound. */ | 
|  | if (ratio <= Scalar(.25)) { | 
|  | if (actred >= 0.) | 
|  | temp = Scalar(.5); | 
|  | if (actred < 0.) | 
|  | temp = Scalar(.5) * dirder / (dirder + Scalar(.5) * actred); | 
|  | if (Scalar(.1) * fnorm1 >= fnorm || temp < Scalar(.1)) | 
|  | temp = Scalar(.1); | 
|  | /* Computing MIN */ | 
|  | delta = temp * (std::min)(delta, pnorm / Scalar(.1)); | 
|  | par /= temp; | 
|  | } else if (!(par != 0. && ratio < Scalar(.75))) { | 
|  | delta = pnorm / Scalar(.5); | 
|  | par = Scalar(.5) * par; | 
|  | } | 
|  |  | 
|  | /* test for successful iteration. */ | 
|  | if (ratio >= Scalar(1e-4)) { | 
|  | /* successful iteration. update x, fvec, and their norms. */ | 
|  | x = wa2; | 
|  | wa2 = diag.cwiseProduct(x); | 
|  | fvec = wa4; | 
|  | xnorm = wa2.stableNorm(); | 
|  | fnorm = fnorm1; | 
|  | ++iter; | 
|  | } | 
|  |  | 
|  | /* tests for convergence. */ | 
|  | if (abs(actred) <= parameters.ftol && prered <= parameters.ftol && Scalar(.5) * ratio <= 1. && delta <= parameters.xtol * xnorm) | 
|  | return LevenbergMarquardtSpace::RelativeErrorAndReductionTooSmall; | 
|  | if (abs(actred) <= parameters.ftol && prered <= parameters.ftol && Scalar(.5) * ratio <= 1.) | 
|  | return LevenbergMarquardtSpace::RelativeReductionTooSmall; | 
|  | if (delta <= parameters.xtol * xnorm) | 
|  | return LevenbergMarquardtSpace::RelativeErrorTooSmall; | 
|  |  | 
|  | /* tests for termination and stringent tolerances. */ | 
|  | if (nfev >= parameters.maxfev) | 
|  | return LevenbergMarquardtSpace::TooManyFunctionEvaluation; | 
|  | if (abs(actred) <= NumTraits<Scalar>::epsilon() && prered <= NumTraits<Scalar>::epsilon() && Scalar(.5) * ratio <= 1.) | 
|  | return LevenbergMarquardtSpace::FtolTooSmall; | 
|  | if (delta <= NumTraits<Scalar>::epsilon() * xnorm) | 
|  | return LevenbergMarquardtSpace::XtolTooSmall; | 
|  | if (gnorm <= NumTraits<Scalar>::epsilon()) | 
|  | return LevenbergMarquardtSpace::GtolTooSmall; | 
|  |  | 
|  | } while (ratio < Scalar(1e-4)); | 
|  |  | 
|  | return LevenbergMarquardtSpace::Running; | 
|  | } | 
|  |  | 
|  | template<typename FunctorType, typename Scalar> | 
|  | LevenbergMarquardtSpace::Status | 
|  | LevenbergMarquardt<FunctorType,Scalar>::lmstr1( | 
|  | FVectorType  &x, | 
|  | const Scalar tol | 
|  | ) | 
|  | { | 
|  | n = x.size(); | 
|  | m = functor.values(); | 
|  |  | 
|  | /* check the input parameters for errors. */ | 
|  | if (n <= 0 || m < n || tol < 0.) | 
|  | return LevenbergMarquardtSpace::ImproperInputParameters; | 
|  |  | 
|  | resetParameters(); | 
|  | parameters.ftol = tol; | 
|  | parameters.xtol = tol; | 
|  | parameters.maxfev = 100*(n+1); | 
|  |  | 
|  | return minimizeOptimumStorage(x); | 
|  | } | 
|  |  | 
|  | template<typename FunctorType, typename Scalar> | 
|  | LevenbergMarquardtSpace::Status | 
|  | LevenbergMarquardt<FunctorType,Scalar>::minimizeOptimumStorageInit(FVectorType  &x) | 
|  | { | 
|  | n = x.size(); | 
|  | m = functor.values(); | 
|  |  | 
|  | wa1.resize(n); wa2.resize(n); wa3.resize(n); | 
|  | wa4.resize(m); | 
|  | fvec.resize(m); | 
|  | // Only R is stored in fjac. Q is only used to compute 'qtf', which is | 
|  | // Q.transpose()*rhs. qtf will be updated using givens rotation, | 
|  | // instead of storing them in Q. | 
|  | // The purpose it to only use a nxn matrix, instead of mxn here, so | 
|  | // that we can handle cases where m>>n : | 
|  | fjac.resize(n, n); | 
|  | if (!useExternalScaling) | 
|  | diag.resize(n); | 
|  | eigen_assert( (!useExternalScaling || diag.size()==n) && "When useExternalScaling is set, the caller must provide a valid 'diag'"); | 
|  | qtf.resize(n); | 
|  |  | 
|  | /* Function Body */ | 
|  | nfev = 0; | 
|  | njev = 0; | 
|  |  | 
|  | /*     check the input parameters for errors. */ | 
|  | if (n <= 0 || m < n || parameters.ftol < 0. || parameters.xtol < 0. || parameters.gtol < 0. || parameters.maxfev <= 0 || parameters.factor <= 0.) | 
|  | return LevenbergMarquardtSpace::ImproperInputParameters; | 
|  |  | 
|  | if (useExternalScaling) | 
|  | for (Index j = 0; j < n; ++j) | 
|  | if (diag[j] <= 0.) | 
|  | return LevenbergMarquardtSpace::ImproperInputParameters; | 
|  |  | 
|  | /*     evaluate the function at the starting point */ | 
|  | /*     and calculate its norm. */ | 
|  | nfev = 1; | 
|  | if ( functor(x, fvec) < 0) | 
|  | return LevenbergMarquardtSpace::UserAsked; | 
|  | fnorm = fvec.stableNorm(); | 
|  |  | 
|  | /*     initialize levenberg-marquardt parameter and iteration counter. */ | 
|  | par = 0.; | 
|  | iter = 1; | 
|  |  | 
|  | return LevenbergMarquardtSpace::NotStarted; | 
|  | } | 
|  |  | 
|  |  | 
|  | template<typename FunctorType, typename Scalar> | 
|  | LevenbergMarquardtSpace::Status | 
|  | LevenbergMarquardt<FunctorType,Scalar>::minimizeOptimumStorageOneStep(FVectorType  &x) | 
|  | { | 
|  | using std::abs; | 
|  | using std::sqrt; | 
|  |  | 
|  | eigen_assert(x.size()==n); // check the caller is not cheating us | 
|  |  | 
|  | Index i, j; | 
|  | bool sing; | 
|  |  | 
|  | /* compute the qr factorization of the jacobian matrix */ | 
|  | /* calculated one row at a time, while simultaneously */ | 
|  | /* forming (q transpose)*fvec and storing the first */ | 
|  | /* n components in qtf. */ | 
|  | qtf.fill(0.); | 
|  | fjac.fill(0.); | 
|  | Index rownb = 2; | 
|  | for (i = 0; i < m; ++i) { | 
|  | if (functor.df(x, wa3, rownb) < 0) return LevenbergMarquardtSpace::UserAsked; | 
|  | internal::rwupdt<Scalar>(fjac, wa3, qtf, fvec[i]); | 
|  | ++rownb; | 
|  | } | 
|  | ++njev; | 
|  |  | 
|  | /* if the jacobian is rank deficient, call qrfac to */ | 
|  | /* reorder its columns and update the components of qtf. */ | 
|  | sing = false; | 
|  | for (j = 0; j < n; ++j) { | 
|  | if (fjac(j,j) == 0.) | 
|  | sing = true; | 
|  | wa2[j] = fjac.col(j).head(j).stableNorm(); | 
|  | } | 
|  | permutation.setIdentity(n); | 
|  | if (sing) { | 
|  | wa2 = fjac.colwise().blueNorm(); | 
|  | // TODO We have no unit test covering this code path, do not modify | 
|  | // until it is carefully tested | 
|  | ColPivHouseholderQR<JacobianType> qrfac(fjac); | 
|  | fjac = qrfac.matrixQR(); | 
|  | wa1 = fjac.diagonal(); | 
|  | fjac.diagonal() = qrfac.hCoeffs(); | 
|  | permutation = qrfac.colsPermutation(); | 
|  | // TODO : avoid this: | 
|  | for(Index ii=0; ii< fjac.cols(); ii++) fjac.col(ii).segment(ii+1, fjac.rows()-ii-1) *= fjac(ii,ii); // rescale vectors | 
|  |  | 
|  | for (j = 0; j < n; ++j) { | 
|  | if (fjac(j,j) != 0.) { | 
|  | sum = 0.; | 
|  | for (i = j; i < n; ++i) | 
|  | sum += fjac(i,j) * qtf[i]; | 
|  | temp = -sum / fjac(j,j); | 
|  | for (i = j; i < n; ++i) | 
|  | qtf[i] += fjac(i,j) * temp; | 
|  | } | 
|  | fjac(j,j) = wa1[j]; | 
|  | } | 
|  | } | 
|  |  | 
|  | /* on the first iteration and if external scaling is not used, scale according */ | 
|  | /* to the norms of the columns of the initial jacobian. */ | 
|  | if (iter == 1) { | 
|  | if (!useExternalScaling) | 
|  | for (j = 0; j < n; ++j) | 
|  | diag[j] = (wa2[j]==0.)? 1. : wa2[j]; | 
|  |  | 
|  | /* on the first iteration, calculate the norm of the scaled x */ | 
|  | /* and initialize the step bound delta. */ | 
|  | xnorm = diag.cwiseProduct(x).stableNorm(); | 
|  | delta = parameters.factor * xnorm; | 
|  | if (delta == 0.) | 
|  | delta = parameters.factor; | 
|  | } | 
|  |  | 
|  | /* compute the norm of the scaled gradient. */ | 
|  | gnorm = 0.; | 
|  | if (fnorm != 0.) | 
|  | for (j = 0; j < n; ++j) | 
|  | if (wa2[permutation.indices()[j]] != 0.) | 
|  | gnorm = (std::max)(gnorm, abs( fjac.col(j).head(j+1).dot(qtf.head(j+1)/fnorm) / wa2[permutation.indices()[j]])); | 
|  |  | 
|  | /* test for convergence of the gradient norm. */ | 
|  | if (gnorm <= parameters.gtol) | 
|  | return LevenbergMarquardtSpace::CosinusTooSmall; | 
|  |  | 
|  | /* rescale if necessary. */ | 
|  | if (!useExternalScaling) | 
|  | diag = diag.cwiseMax(wa2); | 
|  |  | 
|  | do { | 
|  |  | 
|  | /* determine the levenberg-marquardt parameter. */ | 
|  | internal::lmpar<Scalar>(fjac, permutation.indices(), diag, qtf, delta, par, wa1); | 
|  |  | 
|  | /* store the direction p and x + p. calculate the norm of p. */ | 
|  | wa1 = -wa1; | 
|  | wa2 = x + wa1; | 
|  | pnorm = diag.cwiseProduct(wa1).stableNorm(); | 
|  |  | 
|  | /* on the first iteration, adjust the initial step bound. */ | 
|  | if (iter == 1) | 
|  | delta = (std::min)(delta,pnorm); | 
|  |  | 
|  | /* evaluate the function at x + p and calculate its norm. */ | 
|  | if ( functor(wa2, wa4) < 0) | 
|  | return LevenbergMarquardtSpace::UserAsked; | 
|  | ++nfev; | 
|  | fnorm1 = wa4.stableNorm(); | 
|  |  | 
|  | /* compute the scaled actual reduction. */ | 
|  | actred = -1.; | 
|  | if (Scalar(.1) * fnorm1 < fnorm) | 
|  | actred = 1. - numext::abs2(fnorm1 / fnorm); | 
|  |  | 
|  | /* compute the scaled predicted reduction and */ | 
|  | /* the scaled directional derivative. */ | 
|  | wa3 = fjac.topLeftCorner(n,n).template triangularView<Upper>() * (permutation.inverse() * wa1); | 
|  | temp1 = numext::abs2(wa3.stableNorm() / fnorm); | 
|  | temp2 = numext::abs2(sqrt(par) * pnorm / fnorm); | 
|  | prered = temp1 + temp2 / Scalar(.5); | 
|  | dirder = -(temp1 + temp2); | 
|  |  | 
|  | /* compute the ratio of the actual to the predicted */ | 
|  | /* reduction. */ | 
|  | ratio = 0.; | 
|  | if (prered != 0.) | 
|  | ratio = actred / prered; | 
|  |  | 
|  | /* update the step bound. */ | 
|  | if (ratio <= Scalar(.25)) { | 
|  | if (actred >= 0.) | 
|  | temp = Scalar(.5); | 
|  | if (actred < 0.) | 
|  | temp = Scalar(.5) * dirder / (dirder + Scalar(.5) * actred); | 
|  | if (Scalar(.1) * fnorm1 >= fnorm || temp < Scalar(.1)) | 
|  | temp = Scalar(.1); | 
|  | /* Computing MIN */ | 
|  | delta = temp * (std::min)(delta, pnorm / Scalar(.1)); | 
|  | par /= temp; | 
|  | } else if (!(par != 0. && ratio < Scalar(.75))) { | 
|  | delta = pnorm / Scalar(.5); | 
|  | par = Scalar(.5) * par; | 
|  | } | 
|  |  | 
|  | /* test for successful iteration. */ | 
|  | if (ratio >= Scalar(1e-4)) { | 
|  | /* successful iteration. update x, fvec, and their norms. */ | 
|  | x = wa2; | 
|  | wa2 = diag.cwiseProduct(x); | 
|  | fvec = wa4; | 
|  | xnorm = wa2.stableNorm(); | 
|  | fnorm = fnorm1; | 
|  | ++iter; | 
|  | } | 
|  |  | 
|  | /* tests for convergence. */ | 
|  | if (abs(actred) <= parameters.ftol && prered <= parameters.ftol && Scalar(.5) * ratio <= 1. && delta <= parameters.xtol * xnorm) | 
|  | return LevenbergMarquardtSpace::RelativeErrorAndReductionTooSmall; | 
|  | if (abs(actred) <= parameters.ftol && prered <= parameters.ftol && Scalar(.5) * ratio <= 1.) | 
|  | return LevenbergMarquardtSpace::RelativeReductionTooSmall; | 
|  | if (delta <= parameters.xtol * xnorm) | 
|  | return LevenbergMarquardtSpace::RelativeErrorTooSmall; | 
|  |  | 
|  | /* tests for termination and stringent tolerances. */ | 
|  | if (nfev >= parameters.maxfev) | 
|  | return LevenbergMarquardtSpace::TooManyFunctionEvaluation; | 
|  | if (abs(actred) <= NumTraits<Scalar>::epsilon() && prered <= NumTraits<Scalar>::epsilon() && Scalar(.5) * ratio <= 1.) | 
|  | return LevenbergMarquardtSpace::FtolTooSmall; | 
|  | if (delta <= NumTraits<Scalar>::epsilon() * xnorm) | 
|  | return LevenbergMarquardtSpace::XtolTooSmall; | 
|  | if (gnorm <= NumTraits<Scalar>::epsilon()) | 
|  | return LevenbergMarquardtSpace::GtolTooSmall; | 
|  |  | 
|  | } while (ratio < Scalar(1e-4)); | 
|  |  | 
|  | return LevenbergMarquardtSpace::Running; | 
|  | } | 
|  |  | 
|  | template<typename FunctorType, typename Scalar> | 
|  | LevenbergMarquardtSpace::Status | 
|  | LevenbergMarquardt<FunctorType,Scalar>::minimizeOptimumStorage(FVectorType  &x) | 
|  | { | 
|  | LevenbergMarquardtSpace::Status status = minimizeOptimumStorageInit(x); | 
|  | if (status==LevenbergMarquardtSpace::ImproperInputParameters) | 
|  | return status; | 
|  | do { | 
|  | status = minimizeOptimumStorageOneStep(x); | 
|  | } while (status==LevenbergMarquardtSpace::Running); | 
|  | return status; | 
|  | } | 
|  |  | 
|  | template<typename FunctorType, typename Scalar> | 
|  | LevenbergMarquardtSpace::Status | 
|  | LevenbergMarquardt<FunctorType,Scalar>::lmdif1( | 
|  | FunctorType &functor, | 
|  | FVectorType  &x, | 
|  | Index *nfev, | 
|  | const Scalar tol | 
|  | ) | 
|  | { | 
|  | Index n = x.size(); | 
|  | Index m = functor.values(); | 
|  |  | 
|  | /* check the input parameters for errors. */ | 
|  | if (n <= 0 || m < n || tol < 0.) | 
|  | return LevenbergMarquardtSpace::ImproperInputParameters; | 
|  |  | 
|  | NumericalDiff<FunctorType> numDiff(functor); | 
|  | // embedded LevenbergMarquardt | 
|  | LevenbergMarquardt<NumericalDiff<FunctorType>, Scalar > lm(numDiff); | 
|  | lm.parameters.ftol = tol; | 
|  | lm.parameters.xtol = tol; | 
|  | lm.parameters.maxfev = 200*(n+1); | 
|  |  | 
|  | LevenbergMarquardtSpace::Status info = LevenbergMarquardtSpace::Status(lm.minimize(x)); | 
|  | if (nfev) | 
|  | * nfev = lm.nfev; | 
|  | return info; | 
|  | } | 
|  |  | 
|  | } // end namespace Eigen | 
|  |  | 
|  | #endif // EIGEN_LEVENBERGMARQUARDT__H | 
|  |  | 
|  | //vim: ai ts=4 sts=4 et sw=4 |