casa6

      subroutine faccumulateFromGrid(nvalue, norm,grid, convFuncV,

     $     wVal, scaledSupport, scaledSampling, 

     $     off, convOrigin, cfShape, loc,

     $     igrdpos,  sinDPA, cosDPA,

     $     finitePointingOffset,

     $     phaseGrad,

     $     phasor,

     $     imNX, imNY, imNP, imNC,

     $     cfNX, cfNY, cfNP, cfNC,

     $     phNX, phNY)

​

      implicit none

      integer imNX, imNY, imNC, imNP,

     $     vNX, vNY, vNC, vNP,

     $     cfNX, cfNY, cfNP, cfNC,

     $     phNX, phNY

​

      complex grid(imNX, imNY, imNP, imNC)

      complex convFuncV(cfNX, cfNY, cfNP, cfNC)

      complex nvalue

      double precision wVal

      integer scaledSupport(2)

      real scaledSampling(2)

      double precision off(2)

      integer convOrigin(4), cfShape(4), loc(4), igrdpos(4)

      double precision sinDPA, cosDPA

      integer finitePointingOffset

      complex norm

      complex phaseGrad(phNX, phNY),phasor

​

      integer l_phaseGradOriginX, l_phaseGradOriginY

      integer iloc(4), iCFPos(4)

      complex wt

      integer ix,iy

      integer l_igrdpos(4)

​

      data iloc/1,1,1,1/, iCFPos/1,1,1,1/

      l_igrdpos(3) = igrdpos(3)+1

      l_igrdpos(4) = igrdpos(4)+1

      l_phaseGradOriginX=phNX/2 + 1

      l_phaseGradOriginY=phNY/2 + 1

​

      do iy=-scaledSupport(2),scaledSupport(2) 

         iloc(2)=nint(scaledSampling(2)*iy+off(2)-1)

         iCFPos(2)=iloc(2)+convOrigin(2)+1

         l_igrdpos(2) = loc(2)+iy+1

         do ix=-scaledSupport(1),scaledSupport(1)

            iloc(1)=nint(scaledSampling(1)*ix+off(1)-1)

            iCFPos(1) = iloc(1) + convOrigin(1) + 1

            l_igrdpos(1) = loc(1) + ix + 1

C            

C Conjugate the CF to account for the W-term and poln. squint.  This is

C the equivalent of the A^\dag operator in the A-Projection paper (A&A 487,

C 419-429 (2008); http://arxiv.org/abs/0805.0834) for the antenna optics (plus

C geometric effects like the w-term) 

C

            wt = convFuncV(iCFPos(1), iCFPos(2), 

     $           iCFPos(3), iCFPos(4))

            if (wVal .le. 0.0)  wt = conjg(wt)

            norm = norm + (wt)

C

C     Apply the conjugate of the phase gradient.  This, along with