%@AUTEUR:Guillaume Connan

prologues:=2;

verbatimtex
%&latex
\documentclass{article}
\usepackage[upright]{fourier}
\begin{document}
etex

input geometriesyr16

figure(-10cm,-5cm,12cm,10cm);
%multiples d'un vecteur
pair t;
t=(1u,2u);
transform T,R,S;
T = identity shifted t;
R = identity shifted 2t;
S = identity shifted -1.5t;
z0 = (0,0); z1= z0 transformed T;
z2 = (-2.5u,0); z3 = z2 transformed R;
z4 = (3u,3u); z5 = z4 transformed S;
drawarrow z0--z1  withcolor 0.4white withpen pencircle scaled 1.8bp;
drawarrow z2--z3 ;
drawarrow z4--z5 ;
label.rt(btex $\overrightarrow{u}$ etex, 0.5[z0,z1]) withcolor 0.4white withpen pencircle scaled 1.8bp;
label.rt(btex $k\overrightarrow{u} \, (k>0)$ etex, 0.5[z2,z3]);
label.rt(btex $k\overrightarrow{u} \, (k<0)$ etex, 0.5[z4,z5]);
fin;

end