casa6

/*

 * PhaseShiftTvi.cc

 *

 *  Created on: Mar 12, 2015

 *      Author: jjacobs

 */

​

#include <msvis/MSVis/PhaseShiftTvi.h>

#include <casacore/casa/Arrays/Cube.h>

#include <casacore/casa/Arrays/Matrix.h>

​

using namespace casacore;

namespace casa {

​

namespace vi {

​

PhaseShiftTvi::PhaseShiftTvi (ViImplementation2 * inputVi, double dXArcseconds,

                              double dYArcseconds)

: TransformingVi2 (inputVi),

  dXArcseconds_p (dXArcseconds),

  dYArcseconds_p (dYArcseconds)

{}

​

void

PhaseShiftTvi::phaseCenterShift (Cube<Complex> & cube) const

{

    // Notes:

    //

    // 1) This is an operation that is likely performed elsewhere in CASA so that we ought to

    //    factor out any commonality.

    //

    // 2) This operation will put the uvw and phaseCenter values out alignment with the shifted

    //    data.  If the data is going to be consumed by a more exacting application than plotMS

    //    these values ought to be adjusted as well by this TVI.

​

    // Get cube shape as scalars

​

    IPosition shape = cube.shape();

    Int nCorrelations = shape (0);

    Int nChannels = shape (1);

    rownr_t nRows = shape (2);

​

    const Int uIndex = 0; // uvw matrix is [3,nRows]

    const Int vIndex = 1;

​

    // Convert the offsets from arcseconds to radians

​

    double radiansPerArcsecond = C::pi / (180 * 3600);

    double dXRadians = dXArcseconds_p * radiansPerArcsecond;

    double dYRadians = dYArcseconds_p * radiansPerArcsecond;

​

    // Capture the uvw and the time for the VB window.

​

    Matrix<Double> theUvw;

    getVii()->uvw (theUvw);

​

    Vector<Double> timeForRows;

    getVii()->time (timeForRows);

​

    // Allow for the case where the iterator window has many timestamps by making the

    // frequencies a function of row number but not doing it when not needed.

​

    double frequencyTime = timeForRows (0);