MODULE graph0; (* DEE 2023-07-21 *)
  (* From Systematic Programming: An Introduction, pg. 77. *)
  FROM MathLib0 IMPORT exp, sin;
  FROM InOut IMPORT Write, WriteLn;

  CONST d = 0.03125; s = 50; h = 65; c = 6.28318; lim = 128;
  VAR x, y: REAL; i, n: INTEGER;
BEGIN i := 0;
  REPEAT x := FLOAT(i) * d; y := exp(-x) * sin(c*x);
         n := TRUNC((FLOAT(s) * y) + 0.5)+h; (* 0.5 to round before truncating. *)
    REPEAT Write(' '); DEC(n)
    UNTIL n = 0;
    Write('*'); WriteLn; INC(i)
  UNTIL i = lim
END graph0.