set terminal x11
set size ratio -1
set style arrow 1 nohead
plot \
  filename using 1:2:($3 - $1):(0) with vectors arrowstyle 1, \
  filename using 1:2:(0):($4 - $2) with vectors arrowstyle 1, \
  filename using 1:4:($3 - $1):(0) with vectors arrowstyle 1, \
  filename using 3:2:(0):($4 - $2) with vectors arrowstyle 1
pause -1
