text: /* +------------------------------------------------------------------------+
     |                     Mobile Robot Programming Toolkit (MRPT)            |
     |                          https://www.mrpt.org/                         |
     |                                                                        |
     | Copyright (c) 2005-2022, Individual contributors, see AUTHORS file     |
     | See: https://www.mrpt.org/Authors - All rights reserved.               |
     | Released under BSD License. See: https://www.mrpt.org/License          |
     +------------------------------------------------------------------------+ */
  #pragma once
  
  #include <mrpt/math/CMatrixD.h>
  #include <mrpt/poses/CPose3DPDF.h>
  #include <mrpt/poses/CPose3DQuatPDF.h>
  #include <mrpt/poses/CPosePDF.h>
  
  namespace mrpt::poses
  {
  class CPosePDFGaussian;
  class CPose3DPDFGaussian;
  
  /** 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$.
   *
   *   This class implements that PDF using a mono-modal Gaussian distribution
   * storing the information matrix instead of its inverse, the covariance matrix.
   *     See mrpt::poses::CPose3DQuatPDF for more details, or
   *     mrpt::poses::CPose3DPDF for classes based on Euler angles instead.
   *
   *  Uncertainty of pose composition operations (\f$ y = x \oplus u \f$) is
   * implemented in the methods "CPose3DQuatPDFGaussianInf::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, CPose3DQuatPDFGaussian
   * \ingroup poses_pdf_grp
   */
  class CPose3DQuatPDFGaussianInf : public CPose3DQuatPDF
  {
  	// This must be added to any CSerializable derived class:
  	DEFINE_SERIALIZABLE(CPose3DQuatPDFGaussianInf, mrpt::poses)
  	using self_t = CPose3DQuatPDFGaussianInf;
  
     public:
  	/** Default constructor - set all values to zero. */
  	CPose3DQuatPDFGaussianInf();
  
  	/** Constructor which left all the member uninitialized, for using when
  	 * speed is critical - as argument, use UNINITIALIZED_QUATERNION. */
  	CPose3DQuatPDFGaussianInf(
  		mrpt::math::TConstructorFlags_Quaternions constructor_dummy_param);
  
  	/** Constructor from a default mean value, information matrix equals to
  	 * zero. */
  	explicit CPose3DQuatPDFGaussianInf(const CPose3DQuat& init_Mean);
  
  	/** Constructor with mean and inverse covariance (information matrix). */
  	CPose3DQuatPDFGaussianInf(
  		const CPose3DQuat& init_Mean,
  		const mrpt::math::CMatrixDouble77& init_CovInv);
  
  	/** The mean value */
  	CPose3DQuat mean;
  	/** The 7x7 information matrix (the inverse of the covariance) */
  	mrpt::math::CMatrixDouble77 cov_inv;
  
  	inline const CPose3DQuat& getPoseMean() const { return mean; }
  	inline CPose3DQuat& getPoseMean() { return mean; }
  
  	void getMean(CPose3DQuat& mean_pose) const override { mean_pose = mean; }
  	bool isInfType() const override { return true; }
  
  	std::tuple<cov_mat_t, type_value> getCovarianceAndMean() const override
  	{
  		return {cov_inv.inverse_LLt(), mean};
  	}
  
  	/** Returns the information (inverse covariance) matrix (a STATE_LEN x
  	 * STATE_LEN matrix) \sa getMean, getCovarianceAndMean */
  	void getInformationMatrix(mrpt::math::CMatrixDouble77& inf) const override
  	{
  		inf = cov_inv;
  	}
  
  	/** Copy operator, translating if necesary (for example, between particles
  	 * and gaussian representations) */
  	void copyFrom(const CPose3DQuatPDF& o) 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 information matrix in the next 7 lines. */
  	bool saveToTextFile(const std::string& file) const override;
  
  	/** 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) override;
  
  	/** Draws a single sample from the distribution */
  	void drawSingleSample(CPose3DQuat& outPart) const 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 drawManySamples(
  		size_t N,
  		std::vector<mrpt::math::CVectorDouble>& outSamples) const override;
  	/** Returns a new PDF such as: NEW_PDF = (0,0,0) - THIS_PDF */
  	void inverse(CPose3DQuatPDF& o) const override;
  
  	/** Unary - operator, returns the PDF of the inverse pose.  */
  	inline CPose3DQuatPDFGaussianInf operator-() const
  	{
  		CPose3DQuatPDFGaussianInf p(mrpt::math::UNINITIALIZED_QUATERNION);
  		this->inverse(p);
  		return p;
  	}
  
  	/** Makes: thisPDF = thisPDF + Ap, where "+" is pose composition (both the
  	 * mean, and the covariance matrix are updated). */
  	void operator+=(const CPose3DQuat& 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 CPose3DQuatPDFGaussianInf& Ap);
  	/** Makes: thisPDF = thisPDF - Ap, where "-" is pose inverse composition
  	 * (both the mean, and the covariance matrix are updated). */
  	void operator-=(const CPose3DQuatPDFGaussianInf& Ap);
  
  	/** Evaluates the PDF at a given point */
  	double evaluatePDF(const CPose3DQuat& x) const;
  	/** Evaluates the ratio PDF(x) / PDF(MEAN), that is, the normalized PDF in
  	 * the range [0,1] */
  	double evaluateNormalizedPDF(const CPose3DQuat& x) const;
  
  };	// End of class def.
  
  bool operator==(
  	const CPose3DQuatPDFGaussianInf& p1, const CPose3DQuatPDFGaussianInf& p2);
  /** Pose composition for two 3D pose Gaussians  \sa
   * CPose3DQuatPDFGaussianInf::operator += */
  CPose3DQuatPDFGaussianInf operator+(
  	const CPose3DQuatPDFGaussianInf& x, const CPose3DQuatPDFGaussianInf& u);
  /** Inverse pose composition for two 3D pose Gaussians  \sa
   * CPose3DQuatPDFGaussianInf::operator -= */
  CPose3DQuatPDFGaussianInf operator-(
  	const CPose3DQuatPDFGaussianInf& x, const CPose3DQuatPDFGaussianInf& u);
  
  /** Dumps the mean and covariance matrix to a text stream. */
  std::ostream& operator<<(
  	std::ostream& out, const CPose3DQuatPDFGaussianInf& obj);
  
  }  // namespace mrpt::poses
  