-5 5 setxrange -1 1 setyrange 20 setxunit traceOx xticks 0 xtick [-2 0 1 3] {xmark} apply 1.7 setlinewidth gsave 0 4 translate orange [xmin 1] {0} apply (-]) ligne grestore gsave 0 -8 translate bleu [-3 2] {0} apply (]-[) ligne grestore