LinearTransform.cc

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/*
 * 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/>.
 */

#include <iostream>
#include <iomanip>

#include "Eigen/LU"

#include "lsst/geom/LinearTransform.h"

namespace lsst {
namespace geom {

LinearTransform::ParameterVector const LinearTransform::getParameterVector() const noexcept {
    ParameterVector r;
    r << (*this)[XX], (*this)[YX], (*this)[XY], (*this)[YY];
    return r;
}

void LinearTransform::setParameterVector(LinearTransform::ParameterVector const& vector) noexcept {
    (*this)[XX] = vector[XX];
    (*this)[XY] = vector[XY];
    (*this)[YX] = vector[YX];
    (*this)[YY] = vector[YY];
}

LinearTransform const LinearTransform::inverted() const {
    Eigen::FullPivLU<Matrix> lu(getMatrix());
    if (!lu.isInvertible()) {
        throw LSST_EXCEPT(SingularTransformException, "Could not compute LinearTransform inverse");
    }
    Matrix inv = lu.inverse();
    return LinearTransform(inv);
}

double LinearTransform::computeDeterminant() const noexcept { return getMatrix().determinant(); }

LinearTransform::TransformDerivativeMatrix LinearTransform::dTransform(Point2D const& input) const noexcept {
    TransformDerivativeMatrix r = TransformDerivativeMatrix::Zero();
    r(0, XX) = input.getX();
    r(0, XY) = input.getY();
    r(1, YX) = input.getX();
    r(1, YY) = input.getY();
    return r;
}

std::ostream& operator<<(std::ostream& os, LinearTransform const& t) {
    std::ios::fmtflags flags = os.flags();
    int prec = os.precision(7);
    os.setf(std::ios::fixed);
    os << "LinearTransform([(" << std::setw(10) << t[LinearTransform::XX] << "," << std::setw(10)
       << t[LinearTransform::XY] << "),\n";
    os << "                 (" << std::setw(10) << t[LinearTransform::YX] << "," << std::setw(10)
       << t[LinearTransform::YY] << ")])";
    os.precision(prec);
    os.flags(flags);
    return os;
}

}  // namespace geom
}  // namespace lsst