anchor.diff:      end if
       if (cheby_r1(jj)<zero) then
         write(lerr,"(a)")      "CHEBY> ERROR R1 cannot be lower than zero!"
  +      goto 10
  +    end if
  +    if (cheby_r2(jj)<zero) then
  +      ! a sanity check, most probably will never be triggered, but better stay safe
  +      write(lerr,"(a)")      "CHEBY> ERROR R2 cannot be lower than zero!"
         goto 10
       end if
       if (cheby_I (jj)<=zero) then
  
positive.code:   integer          :: idaa, jj, morder, nn, mm, ll, oo
    integer          :: hh(lnv)=0
    real(kind=fPrec) :: rra, xa, ya, ax, ay, xclo, yclo, angrad, cscal, dxpa, dypa, refr, rnn, coeff
    real(kind=fPrec) :: epsilon, gteps, lteps
    logical          lrotate
  
    common/daele/alda,asda,aldaq,asdaq,smida,xx,yy,dpda,dpda1,sigmda,ej1,ejf1,rv
  
negative.code:   integer, intent(in) :: ix
  
    real(kind=fPrec) xx, yy, rr, zz, dx, dy, xxr, yyr, xxn, yyn, ax, ay
    real(kind=fPrec) theta, radio, angle_rad, epsilon, gteps, lteps, r1lteps, r2gteps
    integer          ii, jj, inside, fUnit
    logical          lrotate, err
  
    epsilon=c1m15
    gteps=one+epsilon
    lteps=one-epsilon
    r1lteps=cheby_r1(icheby(ix))*lteps
    r2gteps=cheby_r2(icheby(ix))*gteps
    
    write(lout,"(a)") "CHEBY> Dumping potential map..."
    call f_requestUnit(cheby_mapFileName(iLens),fUnit)
  