8.8 3D plotting

set samples 21
set isosample 11
set xlabel "x axis" -3,-2
set ylabel "y axis" 3,-2
set zlabel "z axis" -5
set title "3d gnu plot demo"
splot x*y with points

set samples 21
set isosample 11
set xlabel "x axis" -3,-2
set ylabel "y axis" 3,-2
set zlabel "z axis" -5
set title "3d gnu plot demo"
set label 1 "this is the surface boundary" at -10,-5,150 center
set arrow 1 from -10,-5,120 to -10,0,0 nohead
set arrow 2 from -10,-5,120 to 10,0,0 nohead
set arrow 3 from -10,-5,120 to 0,10,0 nohead
set arrow 4 from -10,-5,120 to 0,-10,0 nohead
set xrange [-10:10]
set yrange [-10:10]
splot x*y

此例说明以 gnuplot 画 3d 图形。gnuplot 使用 xlable, ylable, zlable 设定座标轴名称及放在特定的位置。图中第二部份举出加入线条及文字说明的方法。