Function lsst::jointcal::inversePolyTransform

Function Documentation

std::shared_ptr<AstrometryTransformPolynomial> lsst::jointcal::inversePolyTransform(AstrometryTransform const &forward, Frame const &domain, double const precision, std::size_t maxOrder = 9, std::size_t nSteps = 50)

Approximate the inverse by a polynomial, to some precision.

Return

A polynomial that best approximates forward.

Parameters
  • forward: Transform to be inverted.

  • [in] domain: The domain of forward.

  • [in] precision: Require that \(chi2 / (nsteps^2) < precision^2\).

  • [in] maxOrder: The maximum order allowed of the inverse polynomial.

  • [in] nSteps: The number of sample points per axis (nSteps^2 total points).