casa6

//# SimACoh.cc: Simulated additive errors

//# Copyright (C) 1996,1997,1999,2000

//# Associated Universities, Inc. Washington DC, USA.

//#

//# This library is free software; you can redistribute it and/or modify it

//# under the terms of the GNU Library General Public License as published by

//# the Free Software Foundation; either version 2 of the License, or (at your

//# option) any later version.

//#

//# This library 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 Library General Public

//# License for more details.

//#

//# You should have received a copy of the GNU Library General Public License

//# along with this library; if not, write to the Free Software Foundation,

//# Inc., 675 Massachusetts Ave, Cambridge, MA 02139, USA.

//#

//# Correspondence concerning AIPS++ should be adressed as follows:

//#        Internet email: aips2-request@nrao.edu.

//#        Postal address: AIPS++ Project Office

//#                        National Radio Astronomy Observatory

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//#

//# $Id$

​

#include <casa/BasicMath/Math.h>

#include <synthesis/MeasurementComponents/SimACoh.h>

#include <msvis/MSVis/VisBuffer.h>

​

using namespace casacore;

namespace casa { //# NAMESPACE CASA - BEGIN

​

// Note: this simplistic implementation just generates a new random

// noise value for every call of apply, it doesn't keep track of

// time and antenna to return the same value if called with the same

// coordinates. Thus applyInv will only work correctly if

// called from a separate object in the exact same sequence as apply.

​

SimACoh::SimACoh(Int seed, Double rms):rndGen_p(seed),

                       //noiseDist_p(&rndGen_p, 0.0, square(rms/2.0))

noiseDist_p(&rndGen_p, 0.0, square(rms))

{

}

VisBuffer& SimACoh::apply(VisBuffer& vb)

{

  Bool zeroSpacing = false;

  Complex c[4];

  for (Int row=0; row<vb.nRow(); row++) {

    zeroSpacing = false;

    if (vb.uvw()(row)(0) == 0.0 && vb.uvw()(row)(1) == 0.0) {

      zeroSpacing = true;

    }

    for (Int chn=0; chn<vb.nChannel(); chn++) {

      if (zeroSpacing) {

    for (Int i=0; i<4; i++) c[i]=Complex(1.41421356*noiseDist_p(), 0.0);

      } else {

    for (Int i=0; i<4; i++) c[i]=Complex(noiseDist_p(),noiseDist_p());

      }

      CStokesVector noiseCoh(c);