anchor.diff:      real(kind = x_precision),dimension(n)    ,intent(in):: temp_c_thick
       integer                                             :: i
       integer                                             :: fid_4 = 11
  -    character(len = 64)                                 :: fname_4      
  +    character(len = 64)                                 :: fname_4
   
       !------------------------------------------------------------------------
   
  
positive.code:   subroutine write_critical_points(n,radius, sigma_c_thin, temp_c_thin,sigma_c_thick, temp_c_thick)
  
      implicit none
       
      integer                                  ,intent(in):: n 
      real(kind = x_precision),dimension(n)    ,intent(in):: radius
  
      real(kind = x_precision),dimension(n)    ,intent(in):: sigma_c_thin
  
negative.code: 
       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
  
       close(fid_4)
  
    end subroutine write_critical_points
  
  
    subroutine save_data(fid, filename, n, data_1, data_2)
      implicit none
  
      integer                                  ,intent(in):: fid
      character(len =64)                       ,intent(in):: filename
      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
  
      close(fid)
  
    end subroutine save_data
  