From 104f8fd36e0c7e25ca2e825ea5848d3d4a3d1706 Mon Sep 17 00:00:00 2001 From: Gael Guennebaud Date: Tue, 19 Aug 2008 17:52:04 +0000 Subject: Added a SVD module: - the decompostion code has been adfapted from JAMA - handles non square matrices of size MxN with M>=N - does not work for complex matrices - includes a solver where the parts corresponding to zero singular values are set to zero --- Eigen/src/Core/MatrixBase.h | 4 + Eigen/src/Core/util/ForwardDeclarations.h | 1 + Eigen/src/SVD/CMakeLists.txt | 6 + Eigen/src/SVD/SVD.h | 506 ++++++++++++++++++++++++++++++ 4 files changed, 517 insertions(+) create mode 100644 Eigen/src/SVD/CMakeLists.txt create mode 100644 Eigen/src/SVD/SVD.h (limited to 'Eigen/src') diff --git a/Eigen/src/Core/MatrixBase.h b/Eigen/src/Core/MatrixBase.h index 61cfd58fc..de31621ce 100644 --- a/Eigen/src/Core/MatrixBase.h +++ b/Eigen/src/Core/MatrixBase.h @@ -557,6 +557,10 @@ template class MatrixBase EigenvaluesReturnType eigenvalues() const; RealScalar operatorNorm() const; +/////////// SVD module /////////// + + const SVD svd() const; + /////////// Geometry module /////////// template diff --git a/Eigen/src/Core/util/ForwardDeclarations.h b/Eigen/src/Core/util/ForwardDeclarations.h index 77c6f297a..694aa245d 100644 --- a/Eigen/src/Core/util/ForwardDeclarations.h +++ b/Eigen/src/Core/util/ForwardDeclarations.h @@ -98,6 +98,7 @@ void ei_cache_friendly_product( template class LU; template class QR; +template class SVD; template class Cholesky; template class CholeskyWithoutSquareRoot; diff --git a/Eigen/src/SVD/CMakeLists.txt b/Eigen/src/SVD/CMakeLists.txt new file mode 100644 index 000000000..f983a491d --- /dev/null +++ b/Eigen/src/SVD/CMakeLists.txt @@ -0,0 +1,6 @@ +FILE(GLOB Eigen_SVD_SRCS "*.h") + +INSTALL(FILES + ${Eigen_SVD_SRCS} + DESTINATION ${INCLUDE_INSTALL_DIR}/Eigen/src/SVD + ) diff --git a/Eigen/src/SVD/SVD.h b/Eigen/src/SVD/SVD.h new file mode 100644 index 000000000..9c1519450 --- /dev/null +++ b/Eigen/src/SVD/SVD.h @@ -0,0 +1,506 @@ +// This file is part of Eigen, a lightweight C++ template library +// for linear algebra. Eigen itself is part of the KDE project. +// +// Copyright (C) 2008 Gael Guennebaud +// +// Eigen is free software; you can redistribute it and/or +// modify it under the terms of the GNU Lesser General Public +// License as published by the Free Software Foundation; either +// version 3 of the License, or (at your option) any later version. +// +// Alternatively, you can redistribute it and/or +// modify it under the terms of the GNU General Public License as +// published by the Free Software Foundation; either version 2 of +// the License, or (at your option) any later version. +// +// Eigen is distributed in the hope that it will be useful, but WITHOUT ANY +// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS +// FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License or the +// GNU General Public License for more details. +// +// You should have received a copy of the GNU Lesser General Public +// License and a copy of the GNU General Public License along with +// Eigen. If not, see . + +#ifndef EIGEN_SVD_H +#define EIGEN_SVD_H + +/** \ingroup SVD_Module + * + * \class SVD + * + * \brief Standard SVD decomposition of a matrix and associated features + * + * \param MatrixType the type of the matrix of which we are computing the SVD decomposition + * + * This class performs a standard SVD decomposition of a real matrix A of size \c M x \c N + * with \c M \>= \c N. + * + * + * \sa MatrixBase::SVD() + */ +template class SVD +{ + private: + typedef typename MatrixType::Scalar Scalar; + typedef typename NumTraits::Real RealScalar; + + enum { + PacketSize = ei_packet_traits::size, + AlignmentMask = int(PacketSize)-1, + MinSize = EIGEN_ENUM_MIN(MatrixType::RowsAtCompileTime, MatrixType::ColsAtCompileTime) + }; + + typedef Matrix ColVector; + typedef Matrix RowVector; + + typedef Matrix MatrixUType; + typedef Matrix MatrixVType; + typedef Matrix SingularValuesType; + + public: + + SVD(const MatrixType& matrix) + : m_matU(matrix.rows(), std::min(matrix.rows(), matrix.cols())), + m_matV(matrix.cols(),matrix.cols()), + m_sigma(std::min(matrix.rows(),matrix.cols())) + { + compute(matrix); + } + + template + void solve(const MatrixBase &b, ResultType* result) const; + + const MatrixUType& matrixU() const { return m_matU; } + const SingularValuesType& singularValues() const { return m_sigma; } + const MatrixVType& matrixV() const { return m_matV; } + + void compute(const MatrixType& matrix); + + protected: + /** \internal */ + MatrixUType m_matU; + /** \internal */ + MatrixVType m_matV; + /** \internal */ + SingularValuesType m_sigma; +}; + +/** Computes / recomputes the SVD decomposition A = U S V^* of \a matrix + * + * \note this code has been adapted from JAMA (public domain) + */ +template +void SVD::compute(const MatrixType& matrix) +{ + const int m = matrix.rows(); + const int n = matrix.cols(); + const int nu = std::min(m,n); + + m_matU.resize(m, nu); + m_matU.setZero(); + m_sigma.resize(std::min(m,n)); + m_matV.resize(n,n); + + RowVector e(n); + ColVector work(m); + MatrixType matA(matrix); + const bool wantu = true; + const bool wantv = true; + int i=0, j=0, k=0; + + // Reduce A to bidiagonal form, storing the diagonal elements + // in s and the super-diagonal elements in e. + int nct = std::min(m-1,n); + int nrt = std::max(0,std::min(n-2,m)); + for (k = 0; k < std::max(nct,nrt); k++) + { + if (k < nct) + { + // Compute the transformation for the k-th column and + // place the k-th diagonal in m_sigma[k]. + m_sigma[k] = matA.col(k).end(m-k).norm(); + if (m_sigma[k] != 0.0) // FIXME + { + if (matA(k,k) < 0.0) + m_sigma[k] = -m_sigma[k]; + matA.col(k).end(m-k) /= m_sigma[k]; + matA(k,k) += 1.0; + } + m_sigma[k] = -m_sigma[k]; + } + + for (j = k+1; j < n; j++) + { + if ((k < nct) && (m_sigma[k] != 0.0)) + { + // Apply the transformation. + Scalar t = matA.col(k).end(m-k).dot(matA.col(j).end(m-k)); // FIXME dot product or cwise prod + .sum() ?? + t = -t/matA(k,k); + matA.col(j).end(m-k) += t * matA.col(k).end(m-k); + } + + // Place the k-th row of A into e for the + // subsequent calculation of the row transformation. + e[j] = matA(k,j); + } + + // Place the transformation in U for subsequent back multiplication. + if (wantu & (k < nct)) + m_matU.col(k).end(m-k) = matA.col(k).end(m-k); + + if (k < nrt) + { + // Compute the k-th row transformation and place the + // k-th super-diagonal in e[k]. + e[k] = e.end(n-k-1).norm(); + if (e[k] != 0.0) + { + if (e[k+1] < 0.0) + e[k] = -e[k]; + e.end(n-k-1) /= e[k]; + e[k+1] += 1.0; + } + e[k] = -e[k]; + if ((k+1 < m) & (e[k] != 0.0)) + { + // Apply the transformation. + work.end(m-k-1) = matA.corner(BottomRight,m-k-1,n-k-1) * e.end(n-k-1); + for (j = k+1; j < n; j++) + matA.col(j).end(m-k-1) += (-e[j]/e[k+1]) * work.end(m-k-1); + } + + // Place the transformation in V for subsequent back multiplication. + if (wantv) + m_matV.col(k).end(n-k-1) = e.end(n-k-1); + } + } + + + // Set up the final bidiagonal matrix or order p. + int p = min(n,m+1); + if (nct < n) + m_sigma[nct] = matA(nct,nct); + if (m < p) + m_sigma[p-1] = 0.0; + if (nrt+1 < p) + e[nrt] = matA(nrt,p-1); + e[p-1] = 0.0; + + // If required, generate U. + if (wantu) + { + for (j = nct; j < nu; j++) + { + m_matU.col(j).setZero(); + m_matU(j,j) = 1.0; + } + for (k = nct-1; k >= 0; k--) + { + if (m_sigma[k] != 0.0) + { + for (j = k+1; j < nu; j++) + { + Scalar t = m_matU.col(k).end(m-k).dot(m_matU.col(j).end(m-k)); // FIXME is it really a dot product we want ? + t = -t/m_matU(k,k); + m_matU.col(j).end(m-k) += t * m_matU.col(k).end(m-k); + } + m_matU.col(k).end(m-k) = - m_matU.col(k).end(m-k); + m_matU(k,k) = 1.0 + m_matU(k,k); + if (k-1>0) + m_matU.col(k).start(k-1).setZero(); + } + else + { + m_matU.col(k).setZero(); + m_matU(k,k) = 1.0; + } + } + } + + // If required, generate V. + if (wantv) + { + for (k = n-1; k >= 0; k--) + { + if ((k < nrt) & (e[k] != 0.0)) + { + for (j = k+1; j < nu; j++) + { + Scalar t = m_matV.col(k).end(n-k-1).dot(m_matV.col(j).end(n-k-1)); // FIXME is it really a dot product we want ? + t = -t/m_matV(k+1,k); + m_matV.col(j).end(n-k-1) += t * m_matV.col(k).end(n-k-1); + } + } + m_matV.col(k).setZero(); + m_matV(k,k) = 1.0; + } + } + + // Main iteration loop for the singular values. + int pp = p-1; + int iter = 0; + Scalar eps(pow(2.0,-52.0)); + while (p > 0) + { + int k=0; + int kase=0; + + // Here is where a test for too many iterations would go. + + // This section of the program inspects for + // negligible elements in the s and e arrays. On + // completion the variables kase and k are set as follows. + + // kase = 1 if s(p) and e[k-1] are negligible and k

= -1; k--) + { + if (k == -1) + break; + if (ei_abs(e[k]) <= eps*(ei_abs(m_sigma[k]) + ei_abs(m_sigma[k+1]))) + { + e[k] = 0.0; + break; + } + } + if (k == p-2) + { + kase = 4; + } + else + { + int ks; + for (ks = p-1; ks >= k; ks--) + { + if (ks == k) + break; + Scalar t( (ks != p ? ei_abs(e[ks]) : 0.) + (ks != k+1 ? ei_abs(e[ks-1]) : 0.)); + if (ei_abs(m_sigma[ks]) <= eps*t) + { + m_sigma[ks] = 0.0; + break; + } + } + if (ks == k) + { + kase = 3; + } + else if (ks == p-1) + { + kase = 1; + } + else + { + kase = 2; + k = ks; + } + } + k++; + + // Perform the task indicated by kase. + switch (kase) + { + + // Deflate negligible s(p). + case 1: + { + Scalar f(e[p-2]); + e[p-2] = 0.0; + for (j = p-2; j >= k; j--) + { + Scalar t(hypot(m_sigma[j],f)); + Scalar cs(m_sigma[j]/t); + Scalar sn(f/t); + m_sigma[j] = t; + if (j != k) + { + f = -sn*e[j-1]; + e[j-1] = cs*e[j-1]; + } + if (wantv) + { + for (i = 0; i < n; i++) + { + t = cs*m_matV(i,j) + sn*m_matV(i,p-1); + m_matV(i,p-1) = -sn*m_matV(i,j) + cs*m_matV(i,p-1); + m_matV(i,j) = t; + } + } + } + } + break; + + // Split at negligible s(k). + case 2: + { + Scalar f(e[k-1]); + e[k-1] = 0.0; + for (j = k; j < p; j++) + { + Scalar t(hypot(m_sigma[j],f)); + Scalar cs( m_sigma[j]/t); + Scalar sn(f/t); + m_sigma[j] = t; + f = -sn*e[j]; + e[j] = cs*e[j]; + if (wantu) + { + for (i = 0; i < m; i++) + { + t = cs*m_matU(i,j) + sn*m_matU(i,k-1); + m_matU(i,k-1) = -sn*m_matU(i,j) + cs*m_matU(i,k-1); + m_matU(i,j) = t; + } + } + } + } + break; + + // Perform one qr step. + case 3: + { + // Calculate the shift. + Scalar scale = std::max(std::max(std::max(std::max( + ei_abs(m_sigma[p-1]),ei_abs(m_sigma[p-2])),ei_abs(e[p-2])), + ei_abs(m_sigma[k])),ei_abs(e[k])); + Scalar sp = m_sigma[p-1]/scale; + Scalar spm1 = m_sigma[p-2]/scale; + Scalar epm1 = e[p-2]/scale; + Scalar sk = m_sigma[k]/scale; + Scalar ek = e[k]/scale; + Scalar b = ((spm1 + sp)*(spm1 - sp) + epm1*epm1)/2.0; + Scalar c = (sp*epm1)*(sp*epm1); + Scalar shift = 0.0; + if ((b != 0.0) || (c != 0.0)) + { + shift = ei_sqrt(b*b + c); + if (b < 0.0) + shift = -shift; + shift = c/(b + shift); + } + Scalar f = (sk + sp)*(sk - sp) + shift; + Scalar g = sk*ek; + + // Chase zeros. + + for (j = k; j < p-1; j++) + { + Scalar t = hypot(f,g); + Scalar cs = f/t; + Scalar sn = g/t; + if (j != k) + e[j-1] = t; + f = cs*m_sigma[j] + sn*e[j]; + e[j] = cs*e[j] - sn*m_sigma[j]; + g = sn*m_sigma[j+1]; + m_sigma[j+1] = cs*m_sigma[j+1]; + if (wantv) + { + for (i = 0; i < n; i++) + { + t = cs*m_matV(i,j) + sn*m_matV(i,j+1); + m_matV(i,j+1) = -sn*m_matV(i,j) + cs*m_matV(i,j+1); + m_matV(i,j) = t; + } + } + t = hypot(f,g); + cs = f/t; + sn = g/t; + m_sigma[j] = t; + f = cs*e[j] + sn*m_sigma[j+1]; + m_sigma[j+1] = -sn*e[j] + cs*m_sigma[j+1]; + g = sn*e[j+1]; + e[j+1] = cs*e[j+1]; + if (wantu && (j < m-1)) + { + for (i = 0; i < m; i++) + { + t = cs*m_matU(i,j) + sn*m_matU(i,j+1); + m_matU(i,j+1) = -sn*m_matU(i,j) + cs*m_matU(i,j+1); + m_matU(i,j) = t; + } + } + } + e[p-2] = f; + iter = iter + 1; + } + break; + + // Convergence. + case 4: + { + // Make the singular values positive. + if (m_sigma[k] <= 0.0) + { + m_sigma[k] = (m_sigma[k] < 0.0 ? -m_sigma[k] : 0.0); + if (wantv) + m_matV.col(k).start(pp+1) = -m_matV.col(k).start(pp+1); + } + + // Order the singular values. + while (k < pp) + { + if (m_sigma[k] >= m_sigma[k+1]) + break; + Scalar t = m_sigma[k]; + m_sigma[k] = m_sigma[k+1]; + m_sigma[k+1] = t; + if (wantv && (k < n-1)) + m_matV.col(k).swap(m_matV.col(k+1)); + if (wantu && (k < m-1)) + m_matU.col(k).swap(m_matU.col(k+1)); + k++; + } + iter = 0; + p--; + } + break; + } // end big switch + } // end iterations +} + +/** \returns the solution of \f$ A x = b \f$ using the current SVD decomposition of A. + * The parts of the solution corresponding to zero singular values are ignored. + * + * \sa MatrixBase::svd(), LU::solve(), Cholesky::solve() + */ +template +template +void SVD::solve(const MatrixBase &b, ResultType* result) const +{ + const int rows = m_matU.rows(); + ei_assert(b.rows() == rows); + + for (int j=0; j aux = m_matU.transpose() * b.col(j); + + for (int i = 0; i col(j) = m_matV * aux; + } +} + +/** \svd_module + * \returns the SVD decomposition of \c *this + */ +template +inline const SVD::EvalType> +MatrixBase::svd() const +{ + return SVD::type>(derived()); +} + +#endif // EIGEN_SVD_H -- cgit v1.2.3