Présentation de repere_3D.jps

 400 setheight
 800 setwidth
-6 12 setxrange
-4.5 4.5 setyrange
/l 5 def
/L 10 def

/o {0 0 0} def
/i {1 0 0} def
/j {0 1 0} def
/k {0 0 1} def
/a {-1 -1 0} def 
/b {-1 L 0} def 
/c {l L 0} def 
/d {l -1 0} def 

/vect_I {-135 cos -135 sin} def
/vect_J {-5 cos -5 sin 1 mulv} def
/vect_K {0 1} def

/xyz2xy {
3 dict begin
   /z exch def
   /y exch def
   /x exch def
   vect_I x mulv
   vect_J y mulv
   vect_K z mulv
   addv addv
end
} def

[/O /I /J /K /A /B /C /D] 
[o i j k a b c d] {xyz2xy} capply
mapnp

O I A B interdroite O 1.2 hompoint /Im defpoint
O I C D interdroite O 1.2 hompoint /IM defpoint
O J A D interdroite O 1.2 hompoint /Jm defpoint
O J C B interdroite O 1.1 hompoint /JM defpoint
/KM {0 4} def
-2 O K ydpoint /Km defpoint

2 setlinewidth
[B C D] ligne
.8 setlinewidth
[B A D] ligne

%% graduations sur les axes
[1 -.1 0 1 .1 0] {xyz2xy} capply ligne
[-.1 1 0 .1 1 0] {xyz2xy} capply ligne
[0 -.1 1 0 .1 1] {xyz2xy} capply ligne

1 setlinewidth
[Im IM] ligne
[Jm JM] ligne
[O KM] ligne

/arrowscale {.5 dup} def
gsave
   IM stranslate
   O I angle rotate
   arrow
grestore
gsave
   JM stranslate
   O J angle rotate
   arrow
grestore
gsave
   KM stranslate
   O K angle rotate
   arrow
grestore

.8 setlinewidth
gsave
   pointilles
   [Km O] ligne
grestore


12 setfontsize
setTimesItalic
   (O) O ultext
   (x) IM (5 0) brtext
   (y) JM (0 -2) dltext
   (z) KM drtext

/vadjust 7 def
/hadjust 7 def
setCourrier
   (1) I (-2 1) bltext
   (1) J urtext
   (1) K (-2 0) bltext