set colors classic
  set encoding iso_8859_1

  set view equal xyz
  set ticslevel 0
  set palette model HSV functions 5./6.*gray, 1, 1
  set auto cb
  unset colorbox

  set xrange [0:20]
  set yrange [0:20]
  set zrange [0:5]
  set xlabel 'x'
  set ylabel 'y'
  set zlabel 'z'
  set border 1+2+4+8 + 16+32+64+128 + 256+512+1024+2048

  splot \
    'particles.txt' u 2:3:4 w d lt 7 lc rgb '#dddddd', \
    'streamlines.txt' u 2:3:4:1 w lp pt 5 ps .7 lc palette

  pause -1 'Press Enter to continue: '