ddpoly.dem

Delphi Pascal 数据挖掘领域算法包 数值算法大全

PROGRAM d5r2(input,output);
(* driver for routine DDPOLY *)
(* polynomial (x-1)**5 *)
CONST
   nc=6;
   nd=5;   (* nd=nc-1 *)
   np=20;
TYPE
   words = PACKED ARRAY [1..15] OF char;
   glcarray = ARRAY [1..nc] OF real;
   glpdarray = ARRAY [1..nd] OF real;
VAR
   i,j : integer;
   x : real;
   c : glcarray;
   pd : glpdarray;
   d : ARRAY [1..nd,1..np] OF real;
   a : ARRAY [1..nd] OF words;
   glntop : integer;
   gla : ARRAY [1..33] OF real;

FUNCTION power(x: real; n: integer): real;
BEGIN
   IF (n=0) THEN power := 1.0 ELSE power := x*power(x,n-1)
END;

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

(*$I FACTRL.PAS *)

(*$I DDPOLY.PAS *)

BEGIN
   glntop := 0;
   gla[1] := 1.0;
   a[1] := 'polynomial:    '; a[2] := 'first deriv:   ';
   a[3] := 'second deriv:  '; a[4] := 'third deriv:   ';
   a[5] := 'fourth deriv:  ';
   c[1] := -1.0; c[2] := 5.0; c[3] := -10.0;
   c[4] := 10.0; c[5] := -5.0; c[6] := 1.0;
   FOR i := 1 to np DO BEGIN
      x := 0.1*i;
      ddpoly(c,nc,x,pd,nc-1);
      FOR j := 1 to nc-1 DO BEGIN
         d[j,i] := pd[j]
      END
   END;
   FOR i := 1 to nc-1 DO BEGIN
      writeln(' ':7,a[i]);
      writeln('x':12,'DDPOLY':17,'actual':15);
      FOR j := 1 to np DO BEGIN
         x := 0.1*j;
         writeln(x:15:6,d[i,j]:15:6,
           (factrl(nc-1)/factrl(nc-i))*power(x-1.0,nc-i):15:6)
      END;
      writeln('press ENTER to continue...');
      readln
   END
END.