-->t= -%pi:0.05:%pi; // -pi to pi  ... `;' silents output
 
-->f= sign(t);
 
-->plot(t,f,"k"); // plot `sign' function in black
 
-->plot(t,(4/%pi)*sin(t),"g"); //
 
-->plot(t,(4/%pi)*(sin(t)+sin(3*t)/3),"b"); //
 
-->plot(t,(4/%pi)*(sin(t)+sin(3*t)/3+sin(5*t)/5),"r"); //
 
-->plot(t,(4/%pi)*(sin(t)+sin(3*t)/3+sin(5*t)/5+sin(7*t)/7),"y"); //
 
-->plot(t,(4/%pi)*(sin(t)+sin(3*t)/3+sin(5*t)/5+sin(7*t)/7),"c"); //
 
-->plot(t,(4/%pi)*(sin(t)+sin(3*t)/3+sin(5*t)/5+sin(7*t)/7+sin(9*t)/9),"k"); //
 
-->diary(0);