julday.pas

Delphi Pascal 数据挖掘领域算法包 数值算法大全

FUNCTION julday(mm,id,iyyy: integer): integer;
CONST
   igreg=588829;
VAR
   ja,jm,jy,jul: integer;
BEGIN
   IF  (iyyy = 0) THEN BEGIN
      writeln('there is no year zero.'); readln;
   END;
   IF  (iyyy < 0) THEN  iyyy := iyyy+1;
   IF  (mm > 2)  THEN BEGIN
      jy := iyyy;
      jm := mm+1
   END ELSE BEGIN
      jy := iyyy-1;
      jm := mm+13
   END;
   jul := trunc(365.25*jy)+trunc(30.6001*jm)+id+1720995;
   IF  (id+31*(mm+12*iyyy) >= igreg)  THEN BEGIN
      ja := trunc(0.01*jy);
      jul := jul+2-ja+trunc(0.25*ja)
   END;
   julday := jul
END;