anchor.diff:  
        open(fid_4,file  = fname_4, status='unknown',action='readwrite')
        !write(fid_4)'nb_cell,temp_c_thin,sigma_c_thin,temp_c_thick,sigma_thin'
  -    
  +
           do i=1, n
              write(fid_4,'(1p,E12.6,4x,1p,E12.6,4x,1p,E12.6,4x,1p,E12.6,4x,1p,E12.6)')sqrt(radius(i)),&
                         temp_c_thin(i),sigma_c_thin(i),temp_c_thick(i),sigma_c_thick(i)
  -        end do 
  -     
  +        end do
  +
        close(fid_4)
   
     end subroutine write_critical_points
  -    
  +
   
     subroutine save_data(fid, filename, n, data_1, data_2)
       implicit none
   
  -    integer                                  ,intent(in):: fid      
  +    integer                                  ,intent(in):: fid
       character(len =64)                       ,intent(in):: filename
  -    integer                                  ,intent(in):: n 
  +    integer                                  ,intent(in):: n
       real(kind = x_precision)                 ,intent(in):: data_1
       real(kind = x_precision)                 ,intent(in):: data_2
   
       integer                                             :: i
  -  
  +
       !------------------------------------------------------------------------
   
   
       open(fid,file  = filename, status='unknown',access='direct',action='readwrite')
   
  -      
  +
       do i = 1, n
         write(fid,'(1p,E12.6,4x,1p,E12.6,4x,1p,E12.6)') data_1, data_2
  -    end do 
  -       
  +    end do
  +
       close(fid)
   
     end subroutine save_data
  
positive.code:   subroutine curve(nb_it, eps, t_min, t_max, dt, s_min, s_max, temperature, s)
      implicit none
  
      integer                 ,                    intent(in):: nb_it 
      real(kind = x_precision),                    intent(in):: eps  
      real(kind = x_precision),                    intent(in):: t_min 
      real(kind = x_precision),                    intent(in):: t_max 
      real(kind = x_precision),                    intent(in):: dt    
      real(kind = x_precision),                 intent(inout):: S_min  
      real(kind = x_precision),                 intent(inout):: S_max  
  
      real(kind = x_precision),dimension(n_cell),intent(out) :: temperature
      real(kind = x_precision),dimension(n_cell),intent(out) :: s
  
negative.code:     real(kind = x_precision),dimension(n)    ,intent(in):: temp_c_thick
      integer                                             :: i
      integer                                             :: fid_4 = 11
      character(len = 64)                                 :: fname_4
  
      !------------------------------------------------------------------------
  
  