SimpleAstrometryMapping.h

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// -*- LSST-C++ -*-
/*
 * This file is part of jointcal.
 *
 * Developed for the LSST Data Management System.
 * This product includes software developed by the LSST Project
 * (https://www.lsst.org).
 * See the COPYRIGHT file at the top-level directory of this distribution
 * for details of code ownership.
 *
 * This program is free software: 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 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
 
#ifndef LSST_JOINTCAL_SIMPLE_ASTROMETRY_MAPPING_H
#define LSST_JOINTCAL_SIMPLE_ASTROMETRY_MAPPING_H
 
#include <memory>  // for unique_ptr
 
#include "lsst/jointcal/AstrometryMapping.h"
#include "lsst/jointcal/AstrometryTransform.h"
 
namespace lsst {
namespace jointcal {
 
class SimpleAstrometryMapping : public AstrometryMapping {
public:
    SimpleAstrometryMapping(AstrometryTransform const &astrometryTransform, bool toBeFit = true)
            : toBeFit(toBeFit),
              transform(astrometryTransform.clone()),
              errorProp(transform),
              lin(new AstrometryTransformLinear) {}
 
    SimpleAstrometryMapping(SimpleAstrometryMapping const &) = delete;
    SimpleAstrometryMapping(SimpleAstrometryMapping &&) = delete;
    SimpleAstrometryMapping &operator=(SimpleAstrometryMapping const &) = delete;
    SimpleAstrometryMapping &operator=(SimpleAstrometryMapping &&) = delete;
 
    virtual void freezeErrorTransform() {
        // from there on, updating the transform does not change the errors.
        errorProp = transform->clone();
    }
 
    std::size_t getNpar() const override {
        if (toBeFit)
            return transform->getNpar();
        else
            return 0;
    }
 
    void getMappingIndices(IndexVector &indices) const override;
 
    void transformPosAndErrors(FatPoint const &where, FatPoint &outPoint) const override;
 
    void positionDerivative(Point const &where, Eigen::Matrix2d &derivative, double epsilon) const override;
 
    void offsetParams(Eigen::VectorXd const &delta) override {
        if (toBeFit) transform->offsetParams(delta);
    }
 
    Eigen::Index getIndex() const { return index; }
 
    void setIndex(Eigen::Index i) { index = i; }
 
    void computeTransformAndDerivatives(FatPoint const &where, FatPoint &outPoint,
                                                Eigen::MatrixX2d &H) const override;
 
    virtual AstrometryTransform const &getTransform() const { return *transform; }
 
    bool getToBeFit() const { return toBeFit; }
    void setToBeFit(bool value) { toBeFit = value; }
 
    void print(std::ostream &out) const override;
 
protected:
    // Whether this Mapping is fit as part of a Model.
    bool toBeFit;
    Eigen::Index index{};
    /* inheritance may also work. Perhaps with some trouble because
       some routines in Mapping and AstrometryTransform have the same name */
    std::shared_ptr<AstrometryTransform> transform;
 
    std::shared_ptr<AstrometryTransform> errorProp;
    /* to avoid allocation at every call of positionDerivative.
       use a pointer for constness */
    std::unique_ptr<AstrometryTransformLinear> lin;
};
 
class SimplePolyMapping : public SimpleAstrometryMapping {
public:
    ~SimplePolyMapping() = default;
 
    // ! contructor.
    SimplePolyMapping(AstrometryTransformLinear CenterAndScale,
                      AstrometryTransformPolynomial const &transform);
 
    SimplePolyMapping(SimplePolyMapping const &) = delete;
    SimplePolyMapping(SimplePolyMapping &&) = delete;
    SimplePolyMapping &operator=(SimplePolyMapping const &) = delete;
    SimplePolyMapping &operator=(SimplePolyMapping &&) = delete;
 
    /* The SimpleAstrometryMapping version does not account for the
       _centerAndScale transform */
 
    void positionDerivative(Point const &where, Eigen::Matrix2d &derivative, double epsilon) const override;
 
    /* We should put the computation of error propagation and
       parameter derivatives into the same AstrometryTransform routine because
       it could be significantly faster */
    void computeTransformAndDerivatives(FatPoint const &where, FatPoint &outPoint,
                                        Eigen::MatrixX2d &H) const override;
 
    void transformPosAndErrors(FatPoint const &where, FatPoint &outPoint) const override;
 
    AstrometryTransform const &getTransform() const override;
 
private:
    /* to better condition the 2nd derivative matrix, the
    transformed coordinates are mapped (roughly) on [-1,1].
    We need both the transform and its derivative. */
    AstrometryTransformLinear _centerAndScale;
    Eigen::Matrix2d preDer;
 
    /* Where we store the combination. */
    mutable AstrometryTransformPolynomial actualResult;
};
 
#ifdef STORAGE
class SimpleIdentityMapping : public SimpleAstrometryMapping<AstrometryTransformIdentity> {
public:
    virtual void computeTransformAndDerivatives(FatPoint const &where, FatPoint &outPoint,
                                                Eigen::MatrixX2d &H) const {
        outPoint = where;
    }
};
#endif
}  // namespace jointcal
}  // namespace lsst
 
#endif  // LSST_JOINTCAL_SIMPLE_ASTROMETRY_MAPPING_H