anchor.diff:        double precision qfine(1-mbc:mx+mbc,1-mbc:my+mbc,meqn)
         double precision qcoarse(1-mbc:mx+mbc,1-mbc:my+mbc,meqn)
   
  -      integer mq,r2
  +      integer mq
         integer i, i1, i2, ibc, ii, ifine
         integer j, j1, j2, jbc, jj, jfine
         integer ic_add, jc_add, ic, jc, mth
  
positive.code:             do ibc = 1,mbc
                 do jbc = 1,mbc
                    if (is_block_bdry(0) .eq. 1) then
                       qthis(1-ibc,my+ibc,mq) =
       &                     qneighbor(ibc,jbc,mq)
                       qneighbor(1-ibc,1-jbc,mq) =
       &                     qthis(ibc,my+1-jbc,mq)
  
negative.code:             ic_add = igrid*mx/p4est_refineFactor
              do i = 1,mx/p4est_refineFactor
                 do jbc = 1,mbc
                    sum = 0
                    do ii = 1,refratio
                       do jj = 1,refratio
                          ifine = (i-1)*refratio + ii
                          jfine = (jbc-1)*refratio + jj
                          if (iface_coarse .eq. 2) then
                             qf = qfine(ifine,jfine,mq)
                             kf = areafine(ifine,jfine)
                          else
                             qf = qfine(ifine,my+1-jfine,mq)
                             kf = areafine(ifine,my+1-jfine)
                          endif
                          sum = sum + kf*qf
                       enddo
                    enddo
                    if (iface_coarse .eq. 2) then
                       kc = areacoarse(i+ic_add,1-jbc)
                       qcoarse(i+ic_add,1-jbc,mq) = sum/kc
                    else
                       kc = areacoarse(i+ic_add,my+jbc)
                       qcoarse(i+ic_add,my+jbc,mq) = sum/kc
                    endif
                 enddo
              enddo
  