anchor.diff:     36 continue
   c
   
  -c then read the contents of the cc-file block in pairs,
  -c and assign the new indices
  -
  +c separate the complex spherical harmonic coefficients
  +c for the poloidal magnetic potential b(lm,1) into real and
  +c imaginary part and assign two new indices
  +c  
         do 37 lm=1,nlma
          c1=real(b(lm,1))
          c2=aimag(b(lm,1))
  
positive.code:       dimension la(nlma),ma(nlma)
        dimension alm(lmax,lmax),blm(lmax,lmax)
        dimension glm(lmax,lmax),hlm(lmax,lmax)
        dimension cc(2.*nlma)
  c
  c   constants
  c
  
negative.code: c
  c   nominal Earth parameters
  c
        sigma=6.0e+05                 ! Core electrical conductivity in S/m
        rho=11.e+03                   ! Core mean density in kg m^{-3}
        omega=7.2924e-05              ! Rotation angular frequency
        escale=sqrt(rho*omega/sigma)  ! "Elsasser number" scaling
        re=6.371e+06                  ! Earth radius in m
        rc=3.485e+06                  ! Core radius in m
        ri=1.215e+06                  ! Inner core radius in m
        cdepth=rc-ri                  ! Depth of outer core
        rcre=rc/re                    ! core/surface radius ratio
        rcsqinv=(cdepth/rc)**2        ! dim-less inverse squared core radius
  
  c
  c  write header to cc file
  