load (draw)$

koordx : 4$
koordy : 4$
koordz : 4$

A : [3,1,1];
B : [1,1,2];
C : [-1,-2,2];

koord : [
    head_length = 0.2,           /* Pfeil-Kopflaenge */
    color = black,
    xtics = [-koordx+1, 1, koordx-1],
    ytics = [-koordy+1, 1, koordy-1],
    ztics = [-koordz+1, 1, koordz-1],
    line_width = 2,
    vector ([-koordx, 0, 0], [2*koordx, 0, 0]),    /* x-Achse */
    vector ([0, -koordy, 0], [0, 2*koordy, 0]),   /* y-Achse */
    vector ([0, 0, -koordz], [0, 0, 2*koordz]),   /* y-Achse */
    line_width = 1,
    xaxis = true, xtics_axis  = true,
    yaxis = true, ytics_axis  = true,
    zaxis = true, ztics_axis  = true
    ]$

alabel : append (["A"], A + [0,0,0.5]);
blabel : append (["B"], B + [0.5,0,0.5]);
clabel : append (["C"], C + [-0.5,0,0]);
xlabel : append (["x"], [koordx+0.5,-0.5,0]);
ylabel : append (["y"], [0.5,koordy+0.5,0]);
zlabel : append (["z"], [-0.5,0,koordz+0.5]);


draw (
   gr3d (
     user_preamble = [
        "set noborder", 
        "set xyplane at 0", 
        "set grid"
        ],
     koord,
     color = red,
     points ([A, B, C]),
     label (alabel, blabel, clabel),
     color = black,
     label (xlabel, ylabel, zlabel),
     xrange = [-koordx, koordx],
     yrange = [-koordy, koordy],
     zrange = [-koordz, koordz]
   ),

   file_name = "uebgpunkte3d1",
   dimensions = [600,600],
   terminal = png
);