public class PointList
- extends Region
Java interface to the AST PointList class
- a collection of points in a Frame.
The PointList class implements a Region which represents a collection
of points in a Frame.
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modify it under the terms of the GNU General Public Licence as
published by the Free Software Foundation; either version 2 of
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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.
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- See Also:
- AST PointList
Create a PointList.
number of points in a PointList.
|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
public PointList(Frame frame,
- Create a PointList.
This function creates a new PointList object and optionally initialises
A PointList object is a specialised type of Region which represents a
collection of points in a coordinate Frame.
- 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.
The protected interface to this function includes an extra
parameter at the end of the parameter list descirbed above. This
parameter is a pointer to the integer inherited status
variable: "int *status".
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.
npnt - The number of points in the Region.
points - An array giving the coordinates in
frame of the
points is an
naxes is the number of axes in
frame. The value of coordinate number
icoord for point number
ipoint is therefore stored at
unc - An optional pointer to an existing Region which specifies the uncertainties
associated with each point in the PointList being created. The
uncertainty at any point in the PointList 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 is used
equivalent to a box 1.0E-6 of the size of the bounding box of the
PointList being created.
The uncertainty Region has two uses: 1) when the
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
the uncertainties are used to determine if the transformed boundary
can be accurately represented by a specific shape of Region.
AstException - if an error occurred in the AST library
public int getListSize()
number of points in a PointList.
This is a read-only attribute giving the number of points in a
PointList. This value is determined when the PointList is created.
- this object's ListSize attribute
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