LatticePADMContour.h

Classes

LatticePADMContour -- Class to draw a single contour map of a slice from an AIPS++ Lattice. (full description)

template <class T> class LatticePADMContour : public LatticePADisplayMethod<T>

Interface

Public Members
LatticePADMContour(const uInt xAxis, const uInt yAxis, const uInt mAxis, const IPosition fixedPos, LatticeAsContour<T> *arDat)
LatticePADMContour(const uInt xAxis, const uInt yAxis, LatticeAsContour<T> *arDat)
virtual ~LatticePADMContour()
virtual uInt dataDrawSelf(WorldCanvas *wCanvas, const Vector<Double> &blc, const Vector<Double> &trc, const IPosition &start, const IPosition &shape, const IPosition &stride, const Bool usePixelEdges = False)

Description

Review Status

Date Reviewed:
yyyy/mm/dd

Prerequisite

Etymology

The purpose of this class is to draw "contour" maps of data that is "lattice"-based. The "PADM" refers to PrincipalAxesDisplayMethod, meaning that one or more instances of this class are used to actually draw slices of a Lattice along its main axes.

Synopsis

This is a helper class for the LatticeAsContour class. One or more instances of this class are created by a single LatticeAsContour object, each being responsible for drawing a different slice of the data.

Example

This class should only be used by the LatticeAsContour class to setup a number of views of an AIPS++ Image or Array. As such, this example simply outlines how this class is used by LatticeAsContour, in, for example, a support function for a constructor: 
    template <class T>
    void LatticeAsContour<T>::setupElements(IPosition fixedPos) {
      if (nPixelAxes > 2) {
        nImages = dataLattice()->shape()(zAxisNum);
        DDelement.resize(nImages);
        for (uInt index = 0; index < nImages; index++) {
          fixedPos(zAxisNum) = index;
          DDelement[index] = (LatticePADisplayMethod<T> *)new 
          LatticePADMContour<T>(dataLattice(), xAxisNum, yAxisNum,
                               zAxisNum, fixedPos, this);
        }
      } else {
        nImages = 1;
        DDelement.resize(nImages);
        DDelement[0] = (LatticePADisplayMethod<T> *)new
          LatticePADMContour<T>(dataLattice(), xAxisNum, yAxisNum, this);
      }
    }

Motivation

Displaying 2-dimensional slices of a lattice-based data volume is a standard display requirement for astronomical data visualization and presentation.

Template Type Argument Requirements (T)

Thrown Exceptions

To Do

Member Description

LatticePADMContour(const uInt xAxis, const uInt yAxis, const uInt mAxis, const IPosition fixedPos, LatticeAsContour<T> *arDat)
LatticePADMContour(const uInt xAxis, const uInt yAxis, LatticeAsContour<T> *arDat)

Constructors: >2d and 2d. xAxis and yAxis specify which axis in the Lattice (0-based) should be mapped to X and Y on the display device: ie. 2-d slices of the data to be displayed have these as axes. mAxis specifies the "movie" axis, which is the axis along which different slices are taken. fixedPos is an IPosition having the same length as the number of dimensions in the array, and indicates the fixed axis values for axes in the data that are not specified as xAxis or yAxis: indeed, fixedPos(mAxis) indicates which pixel value along the movie axis that this particular object looks after.

virtual ~LatticePADMContour()

Destructor

virtual uInt dataDrawSelf(WorldCanvas *wCanvas, const Vector<Double> &blc, const Vector<Double> &trc, const IPosition &start, const IPosition &shape, const IPosition &stride, const Bool usePixelEdges = False)

Actually draw on the display device. The WorldCanvasHolder will tell the LatticeAsRaster that it should now draw, which will in turn determine which of its one or more LatticePADMRaster objects should draw by matching the movie value on the WorldCanvas. The contour is drawn from world coordinate blc to trc.