import base_pi;
size(8cm,0);

for (int i=-4; i<=4; ++i)
  {
    /* View the definition of string texfrac(int,int,string,bool,bool,bool,bool) */
    label(texfrac(i,4), (i*cm,0));
    label(texfrac(i,4,signin=true), (i*cm,-cm));
    label(texfrac(i,4,factor="\pi"), (i*cm,-2cm));
    label(texfrac(i,4,factor="\pi",factorin=false), (i*cm,-3cm));
    label(texfrac(i,4,factor="\pi",signin=true,factorin=true), (i*cm,-4cm));
    label(texfrac(i,4,factor="\pi",signin=true,factorin=false,displaystyle=true,zero=false), (i*cm,-5cm));
  }