Power-Programmierung/CD1.mdf/pascal/library/dos/math/nr/bessy.pas

Pascal/Delphi Source File | 1991-04-29 | 382 b | 19 lines

FUNCTION bessy(n: integer; x: real): real;
VAR
   by,bym,byp,tox: real;
   j: integer;
BEGIN
   IF (n < 2) THEN BEGIN
      writeln('pause in BESSY - index n less than 2'); readln
   END;
   tox := 2.0/x;
   by := bessy1(x);
   bym := bessy0(x);
   FOR j := 1 TO n-1 DO BEGIN
      byp := j*tox*by-bym;
      bym := by;
      by := byp
   END;
   bessy := by
END;