Source
%% PhS gh
%% 

%% Èchelle et Ètendue de l'image
60 setxunit
-2.5 2.5  setxrange
-1 6  setyrange


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%  DANGER !! Il ne faut pas utiliser de variables
%%  DANGER !! qui commence par les lettres :
%%  DANGER !! xmin, xmax, ymin et ymax...
%%  DANGER !! Utiliser x_min, y_min...
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%




%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% procÈdures
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%


%% on donne ici x(t)
/xdet {
1 dict begin
	/t exch def
	t
end
	} def

%% on donne ici y(t)
/ydet1 {
1 dict begin
	/t exch def
	t dup mul 
end
	} def
/ydet2 {
1 dict begin
	/t exch def
	t 1 add
end
	} def

/ydet3 {
1 dict begin
	/t exch def
	1 t 1 add div
end
	} def


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% dÈfinitions des couleurs
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

/coul1 {120 255 div 70 255 div 9 255 div setrgbcolor} def



%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% tracÈs
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%% tracÈ des axes et du point Origine
1 setlinewidth
15 setfontsize
noir
continu
traceaxes
marks
tracerepere



2 setlinewidth
coul1
continu
-2 -1 settrange
{xdet} {ydet1} courbeparam

-1 0 settrange
{xdet} {ydet2} courbeparam

0 2 settrange
{xdet} {ydet3} courbeparam


[-2 -2 ydet1] points
[-1.01 -1.01 ydet1 -1 -1 ydet1] (-[) ligne
[-1 -1 ydet2] points
[-0.01 -0.01 ydet2 0 0 ydet2] (-[) ligne
[0 0] points
[0.01 0.01 ydet3 0 0 ydet3] (-[) ligne
[1.99 1.99 ydet3 2 2 ydet3] (-[) ligne
[2 5] points

1 setlinewidth
vert
pointilles
[-2 0 -2 -2 ydet1] (-) ligne
[-1 0 -1 -1 ydet1] (-) ligne
[0 0 0 0 ydet2] (-) ligne
[2 0 2 5] (-) ligne