zbrac.dem

来自「Delphi Pascal 数据挖掘领域算法包 数值算法大全」· DEM 代码 · 共 32 行

PROGRAM d9r2(input,output);
(* driver for routine ZBRAC *)
VAR
   succes : boolean;
   i : integer;
   x1,x2 : real;

(*$I MODFILE.PAS *)
(*$I BESSJ0.PAS *)

FUNCTION fx(x: real): real;
BEGIN
   fx := bessj0(x)
END;

(*$I ZBRAC.PAS *)

BEGIN
   writeln('bracketing values:':21,'function values:':23);
   writeln('x1':6,'x2':10,
      'bessj0(x1)':21,'bessj0(x2)':12);
   FOR i := 1 to 10 DO BEGIN
      x1 := i;
      x2 := x1+1.0;
      zbrac(x1,x2,succes);
      IF  (succes)  THEN BEGIN
         writeln(x1:7:2,x2:10:2,' ':7,
            fx(x1):12:6,fx(x2):12:6)
      END
   END
END.