anchor.diff:    write(10, *) "Uf:    ", Uf
     close(10)
   
  +do i=0,10
  +  V = i*0.01
   ! Set up matrix as an array of size 16
     Gkinv = (/ complex(dp) :: &
          0,  V, -Uc,  0, &
  
positive.code:   write(log,*) "TOTAL TIME: ", end-start
    close(log)
  
    call system('gnuplot -e ''set terminal png; set output "'//trim(filename)//'.png";'//&
      'set view map scale 1; set xrange [0:pi]; set yrange [0:pi];'//&
      'unset surface ; set pm3d; splot "'//trim(filename)//'"''')
  
negative.code:      -Uc,  0,   0,  V, &
         0, Uf,   V,  0 /)
  
      do j=0,20
        call write_data(j*0.1_dp,0.1_dp)
      end do
    end do
  
  