topic Re: Can any one tells how many types I will Resolve this question ... in SAS Procedures

Can any one tells how many types I will Resolve this question ...

ajuhack — Fri, 14 Dec 2012 22:34:39 GMT

Given that July 9, 1998 is a full moon, andI

there are 29 days between full moons, in what months will the next

few blue moons occur?

Re: Can any one tells how many types I will Resolve this question ...

Reeza — Fri, 14 Dec 2012 22:50:34 GMT

There isn't always 29 days between full moons.

Re: Can any one tells how many types I will Resolve this question ...

ajuhack — Fri, 14 Dec 2012 22:55:01 GMT

but my question is simple is that will a program resolve this question ........:smileysilly:

Re: Can any one tells how many types I will Resolve this question ...

Cynthia_sas — Fri, 14 Dec 2012 22:59:41 GMT

In fact, according to the Wikipedia article, the lapse is 29.53 days:

"Origin

One lunation (an average lunar cycle) is 29.53 days. There are about 365.25 days in a solar year. Therefore, about 12.37 lunations (365.25 days divided by 29.53 days) occur in a solar year. In the widely used Gregorian calendar, there are 12 months (the word month is derived from moon) in a year, and normally there is one full moon each month. Each calendar year contains roughly 11 days more than the number of days in 12 lunar cycles. The extra days accumulate, so every two or three years (7 times in the 19-year Metonic cycle), there is an extra full moon. The extra moon necessarily falls in one of the four seasons, giving that season four full moons instead of the usual three, and, hence, a blue moon."

See the full Wikipedia article here: Blue moon - Wikipedia, the free encyclopedia and the Wikipedia article on Full moon has the math for calculating full moons.

cynthia

Re: Can any one tells how many types I will Resolve this question ...

ajuhack — Fri, 14 Dec 2012 23:03:17 GMT

Yups Right Cynthia ...

Can you help to resolve using SAS program ???

Re: Can any one tells how many types I will Resolve this question ...

Reeza — Fri, 14 Dec 2012 23:18:32 GMT

Only if you know the exact time of one full moon, because of the partial day. Then assuming the maths correct yes, but I think there's some other factors that are missing

Re: Can any one tells how many types I will Resolve this question ...

Cynthia_sas — Sat, 15 Dec 2012 16:44:10 GMT

Hi:

The program is going to be simple math, BUT only if there were enough information. For example, in just calculating the difference between known full moons for 2012, the difference is not a constant 29.53, these differences (based on GMT times for the known full moons in 2012) are shown if you run the program below. So, instead there must be some other factor coming into play. The Wikipedia article on full moons (Full moon - Wikipedia, the free encyclopedia) suggests that because the moon does not have a true circular orbit, that a correction factor has to be applied. If I had the time, it would be an interesting problem. But it seems to me that you're only going to get as far as the correct day if you adjust by 29.53, which for most months would be good enough. But when the full moon is close to midnight, then the "fudge factor" is going to make a difference, so to solve this, you need a formula that will adjust to the minute (or second), accounting for the non-circular orbit of the moon.

Hope this helps. Here are some links I found useful.

http://www.nevis.columbia.edu/~seligman/moontables.html

http://www.moongiant.com/full_moon_calendar.php

http://wwp.greenwichmeantime.com/time-gadgets/moon-calculator/index.htm

http://www.voidware.com/moon_phase.htm

cynthia

data gmt_full_moon;
infile datalines;
input thismonth : datetime15. lastone : datetime15.;
diffsec = thismonth-lastone;
numday = diffsec / 86400;
/* 86400 seconds in 1 day */
return;
datalines;
09jan2012:07:32 10dec2011:14:37
07feb2012:21:56 09jan2012:07:32
08mar2012:09:42 07feb2012:21:56
06apr2012:19:20 08mar2012:09:42
06may2012:03:36 06apr2012:19:20
04jun2012:11:12 06may2012:03:36
03jul2012:18:52 04jun2012:11:12
02aug2012:03:27 03jul2012:18:52
31aug2012:13:58 02aug2012:03:27
30sep2012:03:19 31aug2012:13:58
29oct2012:19:51 30sep2012:03:19
28nov2012:14:47 29oct2012:19:51
28dec2012:10:23 28nov2012:14:47
;
run;

ods listing;
proc print data=gmt_full_moon noobs;
title 'Number of Actual Days Between Full Moons';
title2 'Based on GMT';
format thismonth lastone datetime20.;
run;

Results from the program showing difference between full moons in GMT:

Number of Actual Days Between Full Moons

Based on GMT

thismonth lastone diffsec numday

09JAN2012:07:32:00 10DEC2011:14:37:00 2566500 29.7049

07FEB2012:21:56:00 09JAN2012:07:32:00 2557440 29.6000

08MAR2012:09:42:00 07FEB2012:21:56:00 2547960 29.4903

06APR2012:19:20:00 08MAR2012:09:42:00 2540280 29.4014

06MAY2012:03:36:00 06APR2012:19:20:00 2535360 29.3444

04JUN2012:11:12:00 06MAY2012:03:36:00 2532960 29.3167

03JUL2012:18:52:00 04JUN2012:11:12:00 2533200 29.3194

02AUG2012:03:27:00 03JUL2012:18:52:00 2536500 29.3576

31AUG2012:13:58:00 02AUG2012:03:27:00 2543460 29.4382

30SEP2012:03:19:00 31AUG2012:13:58:00 2553660 29.5563

29OCT2012:19:51:00 30SEP2012:03:19:00 2565120 29.6889

28NOV2012:14:47:00 29OCT2012:19:51:00 2573760 29.7889

28DEC2012:10:23:00 28NOV2012:14:47:00 2576160 29.8167

Re: Can any one tells how many types I will Resolve this question ...

ajuhack — Sat, 15 Dec 2012 17:26:15 GMT

Many thanks for this Links

Cynthia

Mad...