uk.ac.starlink.ast
Class Circle

java.lang.Object
  extended by uk.ac.starlink.ast.AstObject
      extended by uk.ac.starlink.ast.Mapping
          extended by uk.ac.starlink.ast.Frame
              extended by uk.ac.starlink.ast.Region
                  extended by uk.ac.starlink.ast.Circle

public class Circle
extends Region

Java interface to the AST Circle class - a circular or spherical region within a Frame. The Circle class implements a Region which represents a circle or sphere within a Frame.

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 Circle

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
Circle(Frame frame, double[] centre, double[] point, Region unc)
          Create a Circle given a centre and point on the circumference.
Circle(Frame frame, double[] centre, double radius, Region unc)
          Create a Circle given a centre and radius.
Circle(Frame frame, int form, double[] centre, double[] point, Region unc)
          Create a Circle.
 
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

Circle

public Circle(Frame frame,
              int form,
              double[] centre,
              double[] point,
              Region unc)
Create a Circle. This function creates a new Circle and optionally initialises its attributes.

A Circle is a Region which represents a circle or sphere within the supplied Frame.

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.
form - Indicates how the circle is described by the remaining parameters. A value of zero indicates that the circle is specified by a centre position and a position on the circumference. A value of one indicates that the circle is specified by a centre position and a scalar radius.
unc - An optional pointer to an existing Region which specifies the uncertainties associated with the boundary of the Circle being created. The uncertainty in any point on the boundary of the Circle is found by shifting the supplied "uncertainty" Region so that it is centred at the boundary point being considered. The area covered by the shifted uncertainty Region then represents the uncertainty in the boundary 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 Circle. Alternatively, a NULL Object pointer may be supplied, in which case a default uncertainty is used equivalent to a box 1.0E-6 of the size of the Circle being created.

The uncertainty Region has two uses: 1) when the astOverlap function compares two Regions for equality the uncertainty Region is used to determine the tolerance on the comparison, and 2) when a Region is mapped into a different coordinate system and subsequently simplified (using astSimplify), the uncertainties are used to determine if the transformed boundary can be accurately represented by a specific shape of Region.

Throws:
AstException - if an error occurred in the AST library

Circle

public Circle(Frame frame,
              double[] centre,
              double radius,
              Region unc)
Create a Circle given a centre and radius.

Parameters:
frame - frame in which region will exist (a deep copy is taken)
centre - Naxes-element array giving centre of circle region
radius - radius of circle region
unc - uncertainty associated with the circle's boundary; may be null
See Also:
Circle(uk.ac.starlink.ast.Frame,int,double[],double[],uk.ac.starlink.ast.Region)

Circle

public Circle(Frame frame,
              double[] centre,
              double[] point,
              Region unc)
Create a Circle given a centre and point on the circumference.

Parameters:
frame - frame in which region will exist (a deep copy is taken)
centre - Naxes-element array giving centre of circle region
point - Naxes-element array giving a point on the circle region's circumference
unc - uncertainty associated with the circle's boundary; may be null
See Also:
Circle(uk.ac.starlink.ast.Frame,int,double[],double[],uk.ac.starlink.ast.Region)


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