function jd=jdcvt(jday,year)
%	Convert Julian day to jd in method70.
%	Method70 calculates jd as # days since 1/1/70.
%
%	function jd=jdcvt(jday,year)
%

if year > 99, year= year-1900; end;
if (year < 70 | year > 99), error('Year must be between 70 and 99'), end;

yr=[70 71 72 73 74 75 76 77 78 79 ...
    80 81 82 83 84 85 86 87 88 89 ...
    90 91 92 93 94 95 96 97 98 99];

dyr=[   0  365  730 1096 1461 1826 2191 2557 2922 3287 ...
     3652 4018 4383 4748 5113 5479 5844 6209 6574 6940 ...
     7305 7670 8035 8401 8766 9131 9496 9862 10227 10592];

jd= jday + dyr(year - yr(1) + 1);
