Source
%% auteur : 

-8 10 setxrange
-4 7 setyrange
20 setxunit
%50 setyunit

/quadrillagewidth[.3 .8 .8] def
%pointilles
[1 1]{0.7 setlinewidth} Quadrillage

continu
1.2 setlinewidth
%0.5 0.5 setsubtkstep
traceaxes
ticks
%marks
%tracerepere
axesarrow
(-5) -5 0 [1.5 dup] dtext
(0) 0 0 [1.5 dup] dltext
(1) 0.9 0 [1.5 dup] dtext
(5) 5 0 [1.5 dup] dtext
(1) 0 1 [1.5 dup] cltext
(5) 0 5 [1.5 dup] cltext

/A{-7 -2} def
/B{-6 0} def
/C{-4 2} def
/D{-1 1} def
/E{0 2} def
/F{1 4} def
/G{4 6} def
/H{6 4} def
/I{6.5 2} def
/J{7 0} def
/K{8 -3} def
1.3 setlinewidth
[A .. B .. C .. D{right} .. E .. F .. G{right} .. H .. I .. J .. K] (*-*) draw
[A K] points