anchor.diff:  c**** 1/RHO*d(RHO*VP*QP)/dz
   c**** AT (I+1/2,J+1/2,K+1/2)
   c
  -      function derz(q,vp,rho0,n1,n2,n3)
  -c
  -      dimension q(n1,n2,n3),vp(n1,n2,n3),rho0(40)
  +      function derz(q,vp,rho0,n1,n2,n3,n3p1)
  +c
  +      dimension q(n1,n2,n3),vp(n1,n2,n3),rho0(n3p1)
   c
         common/grid/hx,hy,hz,nx,ny,nz,i2d
         common/coord/i,j,k
  
positive.code: c     program tap
  c c.liu 10/26/96 moified
  c
        parameter(n1=70,n2=70,n3=36,n3p1=n3+1)
  c
        integer ih(6),itp(n1,n2,n3,7),kk(n3),itm6(9)
        real u(n1,n2,n3),v(n1,n2,n3),w(n1,n2,n3)
  
negative.code:         print *,' '
  c
          call ajusp(pa,pp,ax,ay,az,xmat,vect,p,cp0,a,b,c,d
       &             ,tetav0,rho0,itp,n1,n2,n3,n3p1)
          if(ibreak.eq.1)then
            testmax=testmax*testmax
            go to 2
  