CPose3DQuatPDFGaussian.h

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/* +---------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)               |
   |                          http://www.mrpt.org/                             |
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   | Copyright (c) 2005-2017, Individual contributors, see AUTHORS file        |
   | See: http://www.mrpt.org/Authors - All rights reserved.                   |
   | Released under BSD License. See details in http://www.mrpt.org/License    |
   +---------------------------------------------------------------------------+ */
#ifndef CPose3DQuatPDFGaussian_H
#define CPose3DQuatPDFGaussian_H

#include <mrpt/poses/CPose3DQuatPDF.h>
#include <mrpt/poses/CPose3DPDF.h>
#include <mrpt/poses/CPosePDF.h>
#include <mrpt/math/CMatrixD.h>

namespace mrpt
{
namespace poses
{
        class CPosePDFGaussian;
        class CPose3DPDFGaussian;

        DEFINE_SERIALIZABLE_PRE_CUSTOM_BASE( CPose3DQuatPDFGaussian , CPose3DQuatPDF )

        /** Declares a class that represents a Probability Density function (PDF) of a 3D pose using a quaternion \f$ p(\mathbf{x}) = [x ~ y ~ z ~ qr ~ qx ~ qy ~ qz]^\top \f$.
         *
         *   This class implements that PDF using a mono-modal Gaussian distribution. See mrpt::poses::CPose3DQuatPDF for more details, or
         *    mrpt::poses::CPose3DPDF for classes based on Euler angles instead.
         *
         *  Uncertainty of pose composition operations (\f$ y = x \oplus u \f$) is implemented in the methods "CPose3DQuatPDFGaussian::operator+=" and "CPose3DQuatPDF::jacobiansPoseComposition".
         *
         *  For further details on implemented methods and the theory behind them,
         *  see <a href="http://www.mrpt.org/6D_poses:equivalences_compositions_and_uncertainty" >this report</a>.
         *
         * \sa CPose3DQuat, CPose3DQuatPDF, CPose3DPDF, CPose3DQuatPDFGaussianInf
         * \ingroup poses_pdf_grp
         */
        class BASE_IMPEXP CPose3DQuatPDFGaussian : public CPose3DQuatPDF
        {
                // This must be added to any CSerializable derived class:
                DEFINE_SERIALIZABLE( CPose3DQuatPDFGaussian )

        protected:
                /** Assures the symmetry of the covariance matrix (eventually certain operations in the math-coprocessor lead to non-symmetric matrixes!)
                  */
                void  assureSymmetry();

         public:
                 /** Default constructor - set all values to zero. */
                CPose3DQuatPDFGaussian();

                /** Constructor which left all the member uninitialized, for using when speed is critical - as argument, use UNINITIALIZED_QUATERNION. */
                CPose3DQuatPDFGaussian(mrpt::math::TConstructorFlags_Quaternions constructor_dummy_param);

                /** Constructor from a default mean value, covariance equals to zero. */
                explicit CPose3DQuatPDFGaussian( const CPose3DQuat &init_Mean );

                /** Constructor with mean and covariance. */
                CPose3DQuatPDFGaussian( const CPose3DQuat &init_Mean, const mrpt::math::CMatrixDouble77 &init_Cov );

                /** Constructor from a Gaussian 2D pose PDF (sets to 0 the missing variables). */
                explicit CPose3DQuatPDFGaussian( const CPosePDFGaussian &o );

                /** Constructor from an equivalent Gaussian in Euler angles representation. */
                explicit CPose3DQuatPDFGaussian( const CPose3DPDFGaussian &o );


                CPose3DQuat             mean; //!< The mean value
                mrpt::math::CMatrixDouble77             cov; //!< The 7x7 covariance matrix

                inline const CPose3DQuat & getPoseMean() const { return mean; }
                inline       CPose3DQuat & getPoseMean()       { return mean; }

                void getMean(CPose3DQuat &mean_pose) const MRPT_OVERRIDE; //!< Returns an estimate of the pose, (the mean, or mathematical expectation of the PDF). \sa getCovariance
                void getCovarianceAndMean(mrpt::math::CMatrixDouble77 &cov,CPose3DQuat &mean_point) const MRPT_OVERRIDE; //!< Returns an estimate of the pose covariance matrix (7x7 cov matrix) and the mean, both at once. \sa getMean
                void copyFrom(const CPose3DQuatPDF &o) MRPT_OVERRIDE; //!< Copy operator, translating if necesary (for example, between particles and gaussian representations)
                void copyFrom(const CPosePDF &o); //!< Copy operator, translating if necesary (for example, between particles and gaussian representations)
                void copyFrom(const CPose3DPDFGaussian &o); //!< Copy operator, translating if necesary (for example, between particles and gaussian representations)
                void saveToTextFile(const std::string &file) const MRPT_OVERRIDE; //!< Save the PDF to a text file, containing the 3D pose in the first line (x y z qr qx qy qz), then the covariance matrix in the next 7 lines.

                /** this = p (+) this. This can be used to convert a PDF from local coordinates to global, providing the point (newReferenceBase) from which
                  *   "to project" the current pdf. Result PDF substituted the currently stored one in the object. */
                void  changeCoordinatesReference(  const CPose3DQuat &newReferenceBase );

                /** this = p (+) this. This can be used to convert a PDF from local coordinates to global, providing the point (newReferenceBase) from which
                  *   "to project" the current pdf. Result PDF substituted the currently stored one in the object.
                  */
                void  changeCoordinatesReference(  const CPose3D &newReferenceBase ) MRPT_OVERRIDE;

                void drawSingleSample( CPose3DQuat &outPart ) const MRPT_OVERRIDE;//!< Draws a single sample from the distribution
                void drawManySamples( size_t N, std::vector<mrpt::math::CVectorDouble> & outSamples ) const MRPT_OVERRIDE; //!< Draws a number of samples from the distribution, and saves as a list of 1x7 vectors, where each row contains a (x,y,z,qr,qx,qy,qz) datum.
                void inverse(CPose3DQuatPDF &o) const MRPT_OVERRIDE; //!< Returns a new PDF such as: NEW_PDF = (0,0,0) - THIS_PDF

                /** Unary - operator, returns the PDF of the inverse pose.  */
                inline CPose3DQuatPDFGaussian operator -() const
                {
                        CPose3DQuatPDFGaussian p(mrpt::math::UNINITIALIZED_QUATERNION);
                        this->inverse(p);
                        return p;
                }

                void operator += ( const CPose3DQuat &Ap); //!< Makes: thisPDF = thisPDF + Ap, where "+" is pose composition (both the mean, and the covariance matrix are updated).
                void operator += ( const CPose3DQuatPDFGaussian &Ap); //!< Makes: thisPDF = thisPDF + Ap, where "+" is pose composition (both the mean, and the covariance matrix are updated) (see formulas in jacobiansPoseComposition ).
                void operator -= ( const CPose3DQuatPDFGaussian &Ap); //!< Makes: thisPDF = thisPDF - Ap, where "-" is pose inverse composition (both the mean, and the covariance matrix are updated).

                double evaluatePDF( const CPose3DQuat &x ) const; //!< Evaluates the PDF at a given point.

                double evaluateNormalizedPDF( const CPose3DQuat &x ) const; //!< Evaluates the ratio PDF(x) / PDF(MEAN), that is, the normalized PDF in the range [0,1].

                /** Computes the Mahalanobis distance between the centers of two Gaussians.
                  *  The variables with a variance exactly equal to 0 are not taken into account in the process, but
                  *   "infinity" is returned if the corresponding elements are not exactly equal. */
                double mahalanobisDistanceTo( const CPose3DQuatPDFGaussian& theOther);

        }; // End of class def.
        DEFINE_SERIALIZABLE_POST_CUSTOM_BASE( CPose3DQuatPDFGaussian , CPose3DQuatPDF )


        bool BASE_IMPEXP operator==(const CPose3DQuatPDFGaussian &p1,const CPose3DQuatPDFGaussian &p2);
        /** Pose composition for two 3D pose Gaussians  \sa CPose3DQuatPDFGaussian::operator += */
        CPose3DQuatPDFGaussian BASE_IMPEXP operator +( const CPose3DQuatPDFGaussian &x, const CPose3DQuatPDFGaussian &u );
        /** Inverse pose composition for two 3D pose Gaussians  \sa CPose3DQuatPDFGaussian::operator -= */
        CPose3DQuatPDFGaussian BASE_IMPEXP operator -( const CPose3DQuatPDFGaussian &x, const CPose3DQuatPDFGaussian &u );

        /** Dumps the mean and covariance matrix to a text stream. */
        std::ostream  BASE_IMPEXP & operator << (std::ostream & out, const CPose3DQuatPDFGaussian& obj);

        } // End of namespace

        namespace global_settings
        {
                /** If set to true (default), a Scaled Unscented Transform is used instead of a linear approximation with Jacobians.
                  * Affects to:
                  *             - CPose3DQuatPDFGaussian::copyFrom(const CPose3DPDFGaussian &o)
                  *             - CPose3DQuatPDFGaussianInf::copyFrom(const CPose3DPDFGaussianInf &o)
                  */
                extern BASE_IMPEXP bool USE_SUT_EULER2QUAT_CONVERSION;
        }

} // End of namespace

#endif