PROGRAM nestab1;
{Demonstrace nestabilni rekurze Phi(n) = Phi^n, kde Phi = (-1+sqrt(5))/2
a rekurzni vzorec je Phi(n+1) = Phi(n-1) - Phi(n)
Nestabilita vznika proto, ze 2.koren rovnice -(1+sqrt(5))/2 je v absolutni
hodnote vetsi nez dany koren}
{Vysledna data vypsana do FIPOK.DAT v poradi n,rel.err.,Phi(n),Phi^n}
USES Crt;
VAR
   fistar,fisouc,finew,fibas,fipr,fieps : REAL;
   n                                    : INTEGER  ;
   C1 : CHAR;
   F1 : TEXT;
BEGIN
    ASSIGN( F1,  'FIPOK.DAT');
    REWRITE (F1);
fisouc := 1;
finew := 0.5 * (sqrt(5) - 1);
fibas := finew;
fipr := finew;
n := 1;
fieps := 0;
WRITELN (N:5,FIEPS:14:-4,FINEW:14:-4,FIPR:14:-4);
WRITELN (F1,N:5,' ',FIEPS:14:-4,' ',FINEW:14:-4,' ',FIPR:14:-4);
FOR N:=2 TO 100 DO BEGIN
fistar := fisouc;
fisouc := finew;
fipr := fipr * fibas;
finew := fistar - fisouc;
fieps := (finew - fipr)/fipr;
WRITELN (N:5,FIEPS:14:-4,FINEW:14:-4,FIPR:14:-4);
WRITELN (F1,N:5,' ',FIEPS:14:-4,' ',FINEW:14:-4,' ',FIPR:14:-4);
if n MOD 23 = 0 THEN BEGIN
          WRITELN('---- more ---'); C1:=READKEY;END;
END;
CLOSE (F1);
END.