anchor.diff:        write(fid_tot,'(3(A16))') 'Surface_density', 'Temperature', 'Optical_depth'
   
         do j = 1, nb_it
  -        temp_real(j)  =  temp_real(j) 
  -        sigma_real(j) =  sigma_real(j) 
  +        temp_real(j)  =  temp_real(j)
  +        sigma_real(j) =  sigma_real(j)
   
           call variables(temp_real(j), sigma_real(j), omega, f, optical_depth, tau_eff)
   
  
positive.code: 
        call display_critical_points(sigma_c_thin, temp_c_thin, sigma_c_thick, temp_c_thick, k)
  
  
        ! Saving the DIMENSIONED values of Sigma and T for the S curve in a file
        write(number_of_cell,'(I5.5)') k
        fid_tot = 22 + k
        fname_tot = 's_curves/Temperature_Sigma_'//trim(number_of_cell)//'_tot.dat'
        
        open(fid_tot,file  = fname_tot, action='write', status = 'replace', iostat = ios)
        if (ios /= 0) then
          write(*,*)"Error while opening the ", fname_tot," file."
  
negative.code:     !-----------------------------------------------------------------------
  
      integer                                               :: i
  
      i = max(1, index_fcp)
  
  