uk.ac.starlink.ast

Class NullRegion

java.lang.Object

uk.ac.starlink.ast.AstObject

uk.ac.starlink.ast.Mapping

uk.ac.starlink.ast.Frame

uk.ac.starlink.ast.Region

uk.ac.starlink.ast.NullRegion

public class NullRegion
extends Region

Java interface to the AST NullRegion class - a boundless region within a Frame. The NullRegion class implements a Region with no bounds within a Frame. If the Negated attribute of a NullRegion is false, the NullRegion represents a Region containing no points. If the Negated attribute of a NullRegion is true, the NullRegion represents an infinite Region (that is, all points in the coordinate system are inside the NullRegion).

Licence

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public Licence as published by the Free Software Foundation; either version 2 of the Licence, 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 Licence for more details.

You should have received a copy of the GNU General Public Licence along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street,Fifth Floor, Boston, MA 02110-1301, USA

See Also:

AST NullRegion

Nested Class Summary

Nested classes/interfaces inherited from class uk.ac.starlink.ast.Mapping

Mapping.Interpolator, Mapping.Spreader

Field Summary

Fields inherited from class uk.ac.starlink.ast.Region

OVERLAP_INSIDE, OVERLAP_NEGATE, OVERLAP_NONE, OVERLAP_OUTSIDE, OVERLAP_PARTIAL, OVERLAP_SAME, OVERLAP_UNKNOWN

Fields inherited from class uk.ac.starlink.ast.Mapping

LINEAR_INTERPOLATOR, LINEAR_SPREADER, NEAREST_INTERPOLATOR, NEAREST_SPREADER

Fields inherited from class uk.ac.starlink.ast.AstObject

AST__BAD, AST__TUNULL, pointer

Constructor Summary

Constructors

Constructor and Description
NullRegion(Frame frame, Region unc) Create a NullRegion.

Method Summary

Methods inherited from class uk.ac.starlink.ast.Region

getAdaptive, getBounded, getClosed, getFillFactor, getMeshSize, getNegated, getRegionBounds, getRegionFrame, getRegionPoints, getUnc, mapRegion, mask, maskB, maskD, maskF, maskI, maskL, maskS, negate, overlap, setAdaptive, setClosed, setFillFactor, setMeshSize, setNegated, setUnc, showMesh

Methods inherited from class uk.ac.starlink.ast.Frame

angle, axAngle, axDistance, axOffset, convert, distance, findFrame, format, getActiveUnit, getAlignSystem, getBottom, getDigits, getDigits, getDirection, getDomain, getDut1, getEpoch, getFormat, getLabel, getMatchEnd, getMaxAxes, getMinAxes, getNaxes, getNormUnit, getObsLat, getObsLon, getPermute, getPreserveAxes, getSymbol, getSystem, getTitle, getTop, getUnit, intersect, norm, offset, offset2, permAxes, pickAxes, resolve, setActiveUnit, setAlignSystem, setBottom, setDigits, setDigits, setDirection, setDomain, setDut1, setEpoch, setEpoch, setFormat, setLabel, setMatchEnd, setMaxAxes, setMinAxes, setObsLat, setObsLon, setPermute, setPreserveAxes, setSymbol, setSystem, setTitle, setTop, setUnit, unformat

Methods inherited from class uk.ac.starlink.ast.Mapping

decompose, getInvert, getNin, getNout, getReport, getTranForward, getTranInverse, invert, linearApprox, mapBox, mapSplit, rate, rebin, rebinD, rebinF, rebinI, resample, resampleB, resampleD, resampleF, resampleI, resampleL, resampleS, setInvert, setReport, simplify, tran1, tran2, tranGrid, tranN, tranP

Methods inherited from class uk.ac.starlink.ast.AstObject

annul, clear, copy, delete, equals, finalize, getAstConstantI, getB, getC, getD, getF, getI, getID, getIdent, getL, getNobject, getObjSize, getRefCount, hashCode, isThreaded, reportVersions, sameObject, set, setB, setC, setD, setF, setI, setID, setIdent, setL, show, test, tune

Methods inherited from class java.lang.Object

clone, getClass, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

NullRegion

public NullRegion(Frame frame,
                  Region unc)

Create a NullRegion. This function creates a new NullRegion and optionally initialises its attributes.

A NullRegion is a Region with no bounds. If the Negated attribute of a NullRegion is false, the NullRegion represents a Region containing no points. If the Negated attribute of a NullRegion is true, the NullRegion represents an infinite Region containing all points within the coordinate system.

Notes

- A null Object pointer (AST__NULL) will be returned if this function is invoked with the AST error status set, or if it should fail for any reason.

Parameters:

frame - A pointer to the Frame in which the region is defined. A deep copy is taken of the supplied Frame. This means that any subsequent changes made to the Frame using the supplied pointer will have no effect the Region.

unc - An optional pointer to an existing Region which specifies the uncertainties associated with positions in the supplied Frame. The uncertainty in any point in the Frame is found by shifting the supplied "uncertainty" Region so that it is centred at the point being considered. The area covered by the shifted uncertainty Region then represents the uncertainty in the position. The uncertainty is assumed to be the same for all points.

If supplied, the uncertainty Region must be of a class for which all instances are centro-symetric (e.g. Box, Circle, Ellipse, etc.) or be a Prism containing centro-symetric component Regions. A deep copy of the supplied Region will be taken, so subsequent changes to the uncertainty Region using the supplied pointer will have no effect on the created Box. Alternatively, a NULL Object pointer may be supplied, in which case a default uncertainty of zero is used.

Throws:

AstException - if an error occurred in the AST library