reset
set view equal xyz
set style arrow 1 nohead
splot \
  filename using 1:2:3:($4 - $1):(0):(0) with vectors arrowstyle 1, \
  filename using 1:2:3:(0):($5 - $2):(0) with vectors arrowstyle 1, \
  filename using 1:5:3:($4 - $1):(0):(0) with vectors arrowstyle 1, \
  filename using 4:2:3:(0):($5 - $2):(0) with vectors arrowstyle 1, \
  filename using 1:2:3:(0):(0):($6 - $3) with vectors arrowstyle 1, \
  filename using 4:2:3:(0):(0):($6 - $3) with vectors arrowstyle 1, \
  filename using 1:5:3:(0):(0):($6 - $3) with vectors arrowstyle 1, \
  filename using 4:5:3:(0):(0):($6 - $3) with vectors arrowstyle 1, \
  filename using 1:2:6:($4 - $1):(0):(0) with vectors arrowstyle 1, \
  filename using 1:2:6:(0):($5 - $2):(0) with vectors arrowstyle 1, \
  filename using 1:5:6:($4 - $1):(0):(0) with vectors arrowstyle 1, \
  filename using 4:2:6:(0):($5 - $2):(0) with vectors arrowstyle 1
