astro

Class WcsModel

java.lang.Object

math.AbstractMultidimensionalDataModel

math.AbstractMultidimensionalGradientModel

astro.WcsModel

All Implemented Interfaces:

GradientMultidimensionalModel, LevenbergMarquardtCapable, MultidimensionalClipping, MultidimensionalDataModel

public class WcsModel
extends AbstractMultidimensionalGradientModel

A mapping of pixel coordinates to WCS coordinates, ICRS 2000 right ascension and declination in almost any possible case. Note that independent and dependent coordinates have the same dimension (2-dim vectors) and thus can be exchanged likewise. In normal mode, one wants to get from the image coordinates (pixels) to α, δ, thus we solve for the parameters that convert x/y (independent, first constructor argument) to ra/de (dependent, second constructor argument). If you want to use errors at all, be aware that errors in the determination of x/y have to be converted to ra/de errors in this standard case. It is normally sufficient to divide the dx dy by the plate scale to get to d(ra), d(de), but generally speaking a solution should also be obtainable without errors to be considered.

Field Summary

Fields

Modifier and Type	Field and Description
private WcsProjection	wcs The WCS projection that converts pixel to ra/de.

Fields inherited from class math.AbstractMultidimensionalDataModel

sigma, x, y

Constructor Summary

Constructors

Constructor and Description
WcsModel(VectorG[] xy, VectorG[] rade) We construct the model using the measured pixel coordinates and the matched catalog ra de.
WcsModel(VectorG[] xy, VectorG[] rade, WcsProjection using) We construct the model using the measured pixel coordinates and the matched catalog ra de.

Method Summary

Modifier and Type	Method and Description
VectorG	evaluateModel(VectorG params, VectorG pixel) We evaluate the WCS model for the given parameters and the pixel position.
VectorG[]	evaluateModelGradient(VectorG params, VectorG pixel)
int	getParameterCount() The parameter count is the parameter count from the projection.
WcsProjection	getProjection() Returns the projection used by this model.

Methods inherited from class math.AbstractMultidimensionalGradientModel

check, check, getCovarianceForSolution, getCovarianceForSolution, getErrorlessNegativeChi2HalfGradient, getErrorlessPseudoHessian, getGradientsAtMeasure, getNegativeChi2HalfGradient, getNegativeChi2HalfGradient, getPseudoHessian, getPseudoHessian

Methods inherited from class math.AbstractMultidimensionalDataModel

clip, dimension, dimensionOfIndependent, equalData, getChiSquareModel, getChiSquareModel, getLorentzianModel, getMeasureCount, getMeasurementErrors, getMeasures, getMetric, getModel, getModel, getResiduals, getResiduals, getRms, getRms, getRobustModel, getTimes, getTotalErrors, simplexChiSquareSolve, simplexChiSquareSolve, simplexLorentzSolve, simplexLorentzSolve, simplexRobustSolve, simplexRobustSolve

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface math.MultidimensionalDataModel

dimension, dimensionOfIndependent, getMeasureCount, getMeasurementErrors, getMeasures, getMetric, getModel, getResiduals, getTimes, getTotalErrors

Methods inherited from interface math.LevenbergMarquardtCapable

getChiSquareModel

Field Detail

wcs

private final WcsProjection wcs

The WCS projection that converts pixel to ra/de.

Constructor Detail

WcsModel

public WcsModel(VectorG[] xy,
                VectorG[] rade)

We construct the model using the measured pixel coordinates and the matched catalog ra de. Each pixel pair must correspond to a catalog pair.

WcsModel

public WcsModel(VectorG[] xy,
                VectorG[] rade,
                WcsProjection using)

We construct the model using the measured pixel coordinates and the matched catalog ra de. Each pixel pair must correspond to a catalog pair.

Method Detail

getParameterCount

public int getParameterCount()

The parameter count is the parameter count from the projection.

evaluateModel

public VectorG evaluateModel(VectorG params,
                             VectorG pixel)

We evaluate the WCS model for the given parameters and the pixel position.

evaluateModelGradient

public VectorG[] evaluateModelGradient(VectorG params,
                                       VectorG pixel)

getProjection

public WcsProjection getProjection()

Returns the projection used by this model.