Problem from a Newbie

[Cecilia Chew <cecilia@nowhere.com>]

Hello All,
I'm a newbie in Ada. There are a lot of question mark in my mind. I'm 
now doing a simple program and the desired output is a signal wave as below.

*      **      **      *
  *    *  *    *  *    *
   *  *    *  *    *  *
    **      **      **
And the coding that i have done is as follow.

with Ada.Text_Io, Ada.Float_Text_IO;
use Ada.Text_Io, Ada.Float_Text_IO;

procedure Graph1 is
    Y : Integer;
    Max_Point : Float;
    Min_Point : Float;
    Pi : Constant := 3.142;
begin

    Max_Point := 1.0;
    for X in 0 .. 360 loop
       for r in 0.0 .. Max_Point loop
          Y := sin (X * 2 * Pi/360);
          Put ("*");
       end loop;
    end loop;
end Graph1;

Could someone tell me what are the mistakes in the coding? Error message 
from the compiler is the 'sin' is undefined. what should i do with this?


-- 
Cecilia Chew
c e c i l i a <AT> g r e e n l i m e . c o m