polcoe.dem

Delphi Pascal 数据挖掘领域算法包 数值算法大全

PROGRAM d3r7 (input,output);
(* driver for routine POLCOE *)
LABEL 1;
CONST
   np=5;
   pi=3.1415926;
TYPE
   glnarray = ARRAY [1..np] OF real;
VAR
   i,j,nfunc : integer;
   f,sum,x : real;
   coeff,xa,ya : glnarray;

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

BEGIN
   FOR nfunc := 1 to 2 DO BEGIN
      IF (nfunc = 1) THEN BEGIN
         writeln ('sine function from 0 to pi');
         writeln;
         FOR i := 1 to np DO BEGIN
            xa[i] := i*pi/np;
            ya[i] := sin(xa[i])
         END
      END ELSE IF (nfunc = 2) THEN BEGIN
         writeln ('exponential function from 0 to 1');
         writeln;
         FOR i := 1 to np DO BEGIN
            xa[i] := 1.0*i/np;
            ya[i] := exp(xa[i])
         END
      END ELSE BEGIN
         GOTO 1
      END;
      polcoe(xa,ya,np,coeff);
      writeln (' ':2,'coefficients');
      FOR i := 1 to np DO BEGIN
         writeln (coeff[i]:12:6)
      END;
      writeln;
      writeln('x':9,'f(x)':13,'polynomial':15);
      FOR i := 1 to 10 DO BEGIN
         IF (nfunc = 1) THEN BEGIN
            x := (-0.05+i/10.0)*pi;
            f := sin(x)
         END ELSE IF (nfunc = 2) THEN BEGIN
            x := -0.05+i/10.0;
            f := exp(x)
         END;
         sum := coeff[np];
         FOR j := np-1 DOWNTO 1 DO BEGIN
            sum := coeff[j]+sum*x
         END;
         writeln (x:12:6,f:12:6,sum:12:6)
      END;
      writeln;
      writeln ('************************************');
      writeln ('press RETURN');
      readln
   END;
1:
END.