anchor.diff:                          ) / dr &
           !             + 1/r * (partial Aphi / partial phi)
                         + 1 / r * ( &
  -                          Aphi(iR, iPhi + 1) - Aphi(iR, iPhi)
  +                          Aphi(iR, iPhi + 1) - Aphi(iR, iPhi) &
                           ) / dPhi
         end do
       end do
  
positive.code:     double precision, intent (in), dimension (:, :) :: Atheta
      type (meshSphereEquator), intent (in) :: meshEquator
      type (vecSphere), intent (out), &
        dimension (size(vals, 1) - 1, size(vals, 2) - 1) :: res
  
      integer :: iR, iPhi, nR, nPhi
      double precision :: r, dr, dPhi
  
negative.code:     double precision :: phiMin, phiMax
      integer :: nR, nPhi
    end type meshSphereEquator
  
    interface calcR
      module procedure calcR_2, calcR_3
    end interface calcR
  
    interface calcPhi
      module procedure calcPhi_2, calcPhi_3
    end interface calcPhi
  contains
    function calcDr(meshEquator)
      implicit none
      type (meshSphereEquator), intent (in) :: meshEquator
      double precision :: calcDr
  
      if (meshEquator%nR .eq. 1) then
        calcDr = 0
      else
        calcDr = (meshEquator%rMax - meshEquator%rMin) / (meshEquator%nR - 1)
      end if
    end function calcDr
  
    function calcDphi(meshEquator)
  