ScaledPolynomialTransformFitter.h

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// -*- LSST-C++ -*-
 
/*
 * LSST Data Management System
 * Copyright 2016 LSST/AURA
 *
 * This product includes software developed by the
 * LSST Project (http://www.lsst.org/).
 *
 * 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 LSST License Statement and
 * the GNU General Public License along with this program.  If not,
 * see <http://www.lsstcorp.org/LegalNotices/>.
 */
#ifndef LSST_MEAS_ASTROM_TanSipFitter_INCLUDED
#define LSST_MEAS_ASTROM_TanSipFitter_INCLUDED
 
#include "lsst/pex/config.h"
#include "lsst/geom/Box.h"
#include "lsst/geom/AffineTransform.h"
#include "lsst/afw/geom/SkyWcs.h"
#include "lsst/afw/table/Catalog.h"
#include "lsst/afw/table/BaseRecord.h"
#include "lsst/meas/astrom/PolynomialTransform.h"
#include "lsst/meas/astrom/SipTransform.h"
 
namespace lsst {
namespace meas {
namespace astrom {

class OutlierRejectionControl {
public:
    OutlierRejectionControl() : nSigma(3), nClipMin(1), nClipMax(5) {}
 
    LSST_CONTROL_FIELD(nSigma, double, "Number of sigma to clip at.");
 
    LSST_CONTROL_FIELD(nClipMin, int, "Always clip at least this many matches.");
 
    LSST_CONTROL_FIELD(nClipMax, int, "Never clip more than this many matches.");
};

class ScaledPolynomialTransformFitter {
public:
    static ScaledPolynomialTransformFitter fromMatches(int maxOrder,
                                                       afw::table::ReferenceMatchVector const& matches,
                                                       afw::geom::SkyWcs const& initialWcs,
                                                       double intrinsicScatter);

    static ScaledPolynomialTransformFitter fromGrid(int maxOrder, geom::Box2D const& bbox, int nGridX,
                                                    int nGridY, ScaledPolynomialTransform const& toInvert);

    void fit(int order = -1);

    void updateModel();

    double updateIntrinsicScatter();

    double getIntrinsicScatter() const { return _intrinsicScatter; }

    std::pair<double, size_t> rejectOutliers(OutlierRejectionControl const& ctrl);

    afw::table::BaseCatalog const& getData() const { return _data; }

    ScaledPolynomialTransform const& getTransform() const { return _transform; }

    PolynomialTransform const& getPoly() const { return _transform.getPoly(); }

    geom::AffineTransform const& getInputScaling() const { return _transform.getInputScaling(); }

    geom::AffineTransform const& getOutputScaling() const { return _outputScaling; }
 
private:
    class Keys;
 
    ScaledPolynomialTransformFitter(afw::table::BaseCatalog const& data, Keys const& keys, int maxOrder,
                                    double intrinsicScatter, geom::AffineTransform const& inputScaling,
                                    geom::AffineTransform const& outputScaling);
 
    double computeIntrinsicScatter() const;
 
    // Normally it's not safe to use a reference as a data member because the
    // class holding it can't control when the referenced object gets
    // destroyed, but this points to one of two singletons (which never get
    // destroyed).
    Keys const& _keys;
    double _intrinsicScatter;
    afw::table::BaseCatalog _data;
    geom::AffineTransform _outputScaling;
    ScaledPolynomialTransform _transform;
    // 2-d generalization of the Vandermonde matrix: evaluates polynomial at
    // all data points when multiplied by a vector of packed polynomial
    // coefficients.
    Eigen::MatrixXd _vandermonde;
};
 
}  // namespace astrom
}  // namespace meas
}  // namespace lsst
 
#endif  // !LSST_MEAS_ASTROM_TanSipFitter_INCLUDEDtr