PROGRAM d15r8(input,output);
(* driver for routine PZEXTR *)
CONST
   glimax=11;
   glnmax=10;
   glncol=7;
   nv=4;
   nuse=5;
TYPE
   glyarray = ARRAY [1..nv] OF real;
VAR
   glx : ARRAY [1..glimax] OF real;
   glqcol : ARRAY [1..glnmax,1..glncol] OF real;
   dum,xest : real;
   i,iest,j : integer;
   dy,yest,yz : glyarray;

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

BEGIN
(* feed values from a rational function *)
(* fn(x) := (1-x+x**3)/(x+1)**n *)
   FOR i := 1 to 10 DO BEGIN
      iest := i;
      xest := 1.0/i;
      dum := 1.0-xest+xest*xest*xest;
      FOR j := 1 to nv DO BEGIN
         dum := dum/(xest+1.0);
         yest[j] := dum
      END;
      pzextr(iest,xest,yest,yz,dy,nv,nuse);
      writeln;
      writeln('i  :=  ',i:2);
      write('Extrap. function:');
      FOR j := 1 to nv DO write(yz[j]:12:6);
      writeln;
      write('Estimated error: ');
      FOR j := 1 to nv DO write(dy[j]:12:6);
      writeln
   END;
   writeln;
   writeln('actual values:   ',1.0:12:6,1.0:12:6,1.0:12:6,1.0:12:6)
END.