ratint.dem

Delphi Pascal 数据挖掘领域算法包 数值算法大全

PROGRAM d3r2(input,output);
(* driver for routine RATINT *)
CONST
   npt=6;
   eps=1.0;
TYPE
   glnarray = ARRAY [1..npt] OF real;
VAR
   dyy,xx,yexp,yy : real;
   i : integer;
   x,y : glnarray;

FUNCTION f(x,eps: real): real;
BEGIN
   f := x*exp(-x)/(sqr(x-1.0)+eps*eps)
END;

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

BEGIN
   FOR i := 1 to npt DO BEGIN
      x[i] := i*2.0/npt;
      y[i] := f(x[i],eps)
   END;
   writeln('Diagonal rational function interpolation');
   writeln;
   writeln('x':5,'interp.':13,'accuracy':14,'actual':12);
   FOR i := 1 to 10 DO BEGIN
      xx := 0.2*i;
      ratint(x,y,npt,xx,yy,dyy);
      yexp := f(xx,eps);
      writeln(xx:6:2,yy:12:6,' ':4,dyy:11,yexp:12:6)
   END
END.