// ticks Ticks(Label format="", ticklabel ticklabel=null,
//             bool beginlabel=true, bool endlabel=true,
//             int N=0, int n=0, real Step=0, real step=0,
//             bool begin=true, bool end=true, tickmodifier modify=None,
//             real Size=0, real size=0, bool extend=false,
//             pen pTick=nullpen, pen ptick=nullpen)

// ticks Ticks(int sign, Label F="", ticklabel ticklabel=null,
//             bool beginlabel=true, bool endlabel=true,
//             real[] Ticks=new real[], real[] ticks=new real[], int N=1,
//             bool begin=true, bool end=true,
//             real Size=0, real size=0, bool extend=false,
//             pen pTick=nullpen, pen ptick=nullpen)
import graph;
unitsize(8cm,1cm);
                   // Par défaut dans graph_settings.asy :
ticksize=1mm;     // 1mm
Ticksize=1.5mm;   // 2*ticksize

real[] GradAvecLabel={0,1/3,2/3,1};
real[] GradSansLabel={1/12,2/12,3/12};

xlimits(min=0,max=1);
xaxis(blue,
      Ticks(ticklabel=Format("%.3f"),
            Ticks=GradAvecLabel,
            ticks=GradSansLabel
           )
);
xaxis(axis=YEquals(-2),
      .9red,
      Ticks(ticklabel=Format("\scriptsize [%.2f]"),
            Ticks=GradAvecLabel,
            ticks=new real[]{5/12,6/12,7/12}
           )
);                   
xaxis(axis=YEquals(-4),
      .5green,
      Ticks(ticklabel=new string(real x){return format("\tiny %.4f",10x);},
            Ticks=new real[]{0,3/12,7/12,11/12,1},
            ticks=GradSansLabel
           )
);
xaxis(axis=YEquals(-6),
      .8pink,
      Ticks(ticklabel=OmitFormat("\scriptsize [%.2f]",1/3),
            Step=1/3,
            step=1/12,
            modify = OmitTick(2/12,11/12),
            pTick=2bp+red, ptick=1bp+blue
           )
);
shipout(bbox(2mm,Fill(white)));