Wp34s date from DOY
11-03-2015, 05:37 PM
Post: #1
 ggauny@live.fr Senior Member Posts: 557 Joined: Nov 2014
Wp34s date from DOY
Hi,

We all know how calculate a "Day of year" say also "YearDay".
A beautifull little routine stays in the WP34s Library for this.
But reverse is it possible, say I know the DOY and, of course, the year of this day of year ?

Yes it is possible with that little routine adapted from A POUPLIER in Jean MEEUS.

Code:
 LBL'DYD'  ; stand for the Date from a Year Day #002 STO I X<>Z LEAP? DEC I [<=>] YZXX ; to fit the convenient stack #032 X>? Y SF 00 DROP RCL I X<>Z DROP + RCL L X<>Y #009 x        ; Multiplicate 2 7 5 / #098 SDR 002 + IP FS?C 00 RCL/ X STO 00 2 7 5 x        ; Multiplicate 9 / IP - RCL 00 9 + #012 / IP RCL I x         ; Multiplicate + #030 + RCL 00 SDR 002 + X<>Y SDR 006 + RTN END

Enter first YEAR and second DOY !

So, 1908 297 ----> 23,101908 my Father born
1914 169 ----> 18,061914 my Mother born
1907 90 ----> 31,031907
1908 91 ----> 31,031908

Gérard.
:

Gérard.
11-03-2015, 06:15 PM (This post was last modified: 11-03-2015 06:41 PM by fhub.)
Post: #2
 fhub Member Posts: 188 Joined: Dec 2013
RE: Wp34s date from DOY
(11-03-2015 05:37 PM)ggauny@live.fr Wrote:  Yes it is possible with that little routine adapted from A POUPLIER in Jean MEEUS.
Why not use the powerful features of the WP34s and make this program MUCH shorter?
Code:
 001 LBL 'DYD' 002 # 001 003 [<->] XXZY 004 [->]DATE 005 x[<->] Y 006 DEC X 007 DAYS+ 008 END

Franz
11-03-2015, 07:40 PM
Post: #3
 ggauny@live.fr Senior Member Posts: 557 Joined: Nov 2014
RE: Wp34s date from DOY
Hi Franz,

I see that I have a lot of thinks in programing !!!!
Really super, I've put this into my special folder where I copy all optimisations.
I've not think of this way. Really nice short and elegant routine !

I wish you good night, I wish me programing like this. First I learn, after I do as you and Dieter..... (May be ?)

Thank's you.

Gérard.

Gérard.
11-03-2015, 07:47 PM
Post: #4
 ggauny@live.fr Senior Member Posts: 557 Joined: Nov 2014
RE: Wp34s date from DOY
Really breathtaking !

Gérard.

Gérard.
11-03-2015, 08:05 PM (This post was last modified: 11-03-2015 08:13 PM by Dieter.)
Post: #5
 Dieter Senior Member Posts: 2,397 Joined: Dec 2013
RE: Wp34s date from DOY
(11-03-2015 07:47 PM)ggauny@live.fr Wrote:  Really breathtaking !

It's the rich function set of the 34s that makes such programs possible – short, elegant and straightforward. For instance, if you know there is a DAYS+ command all you have to do is add the day number (minus one) to 1 Jan of that year. That's what Franz' program does in a few steps. It also shows that such a program actually is not really required – a manual calculation requires just a few keystrokes.

I suggest you take a trip through the IOP section of the 34s manual (index of operations) where you will find all those nice functions. Here and there I am still discovering details I did not know of before. ;-)

Dieter
11-03-2015, 08:21 PM
Post: #6
 ggauny@live.fr Senior Member Posts: 557 Joined: Nov 2014
RE: Wp34s date from DOY
Hi Franz,

The genials things are always simple as said Einstein !

But how you reason to view like this, it is easy to copy but it is harder and better to understand as Masters reason, as masters dread the problems. In my youngth (23 years old) I was Champion of Lorraine in chess (First table), with reading, learnig, training yes but also because I was abble to see and reason better then my adversaries, Can't explain but we can learn this with goods professors. I think that you, Dieter and so others see better than the majority !

In other routine you cut it off the half, 49 steps to 29 steps !!!

Thank's again.

In french, in same situations, we say(a bit slang incorrect), "I'm on the ass !" !
Pardon....

Gérard.
huh:

Gérard.
11-03-2015, 08:22 PM
Post: #7
 ggauny@live.fr Senior Member Posts: 557 Joined: Nov 2014
RE: Wp34s date from DOY

Gérard.
11-03-2015, 08:29 PM
Post: #8
 ggauny@live.fr Senior Member Posts: 557 Joined: Nov 2014
RE: Wp34s date from DOY
Hi Dieter,

Y're right, as many I play with machine without deeply lear the manuals ! And I have the Walter Bonin manual. I'm going to stop programing like this and follow your advertising ! First learn, after programing !

Thank's

Gérard.

Gérard.
11-03-2015, 08:33 PM
Post: #9
 Dieter Senior Member Posts: 2,397 Joined: Dec 2013
RE: Wp34s date from DOY
(11-03-2015 08:29 PM)ggauny@live.fr Wrote:  I'm going to stop programing like this and follow your advertising ! First learn, after programing !

No, no! Learning and doing are two sides of the same thing.
So write programs. Then write better programs. Finally write perfect programs. ;-)

Dieter
11-03-2015, 08:51 PM
Post: #10
 ggauny@live.fr Senior Member Posts: 557 Joined: Nov 2014
RE: Wp34s date from DOY
It is my wish, Dieter.

It is may be nut but I look at yours routines of you and Franz and so many other as a chidren in front of sugar shop !!!

Yes I think that in few time, I will programing as you all.....

My wife call me to go sleep, I go.... (with time, she is like my Mother, worth ! yes, yes)

Cheezr

Gérard.

Gérard.
11-04-2015, 12:16 PM
Post: #11
 ggauny@live.fr Senior Member Posts: 557 Joined: Nov 2014
RE: Wp34s date from DOY
This is only for Fhub/Franz.

Attached File(s) Thumbnail(s)

Gérard.
11-04-2015, 04:33 PM (This post was last modified: 11-04-2015 04:50 PM by fhub.)
Post: #12
 fhub Member Posts: 188 Joined: Dec 2013
RE: Wp34s date from DOY
(11-04-2015 12:16 PM)ggauny@live.fr Wrote:  This is only for Fhub/Franz.
Hi Gérard!

This is one of the problems I don't really like, because you just need to put a long and complicated formula into a calculator program - simply boring.
And there's not much to 'optimize' apart from the usual tricks (using register arithmetics, complex registers etc.)

Since your picture doesn't really say what the result should be, I've found the following website which seems to use the same algorithm (but more clearly), and I've made the program 'GED' (Gregorian Easter Date) from these formulas:
http://ghiorzi.org/easterda.htm
It has 74 steps (incl. the subroutine 'LBL 00' which calculates 'div' in X and 'mod' in Y) - maybe it could be shortened by a few steps with some more optimizations (certainly not more than 3 or 4, I guess), but I think it's not worth trying this.

Code:
 001 LBL'GED' 002 LocR 008 003 STO .00 004 # 019 005 MOD 006 STO .01 007 RCL .00 008 # 100 009 XEQ 00 010 [cmplx]STO .02 011 # 004 012 XEQ 00 013 [cmplx]STO .04 014 # 008 015 RCL+ .02 016 # 025 017 IDIV 018 # 001 019 RCL+ .02 020 RCL- Y 021 # 003 022 IDIV 023 # 015 024 # 019 025 RCL[times] .01 026 + 027 RCL+ .02 028 RCL- .04 029 RCL- Y 030 # 030 031 MOD 032 STO .06 033 RCL .03 034 # 004 035 XEQ 00 036 RCL+ .05 037 RCL+ X 038 # 032 039 + 040 RCL- .06 041 RCL- Y 042 # 007 043 MOD 044 STO .07 045 RCL+ X 046 RCL+ .06 047 # 011 048 [times] 049 RCL+ .01 050 4 051 5 052 1 053 IDIV 054 # 007 055 [times] 056 # 114 057 RCL+ .06 058 RCL+ .07 059 RCL- Y 060 # 031 061 XEQ 00 062 INC Y 063 RCL .00 064 SDR 004 065 + 066 SDR 002 067 + 068 RTN 069 LBL 00 070 [cmplx]ENTER 071 MOD 072 [<->] YZXT 073 IDIV 074 END

Franz
11-05-2015, 01:30 PM
Post: #13
 Dieter Senior Member Posts: 2,397 Joined: Dec 2013
RE: Wp34s date from DOY
(11-04-2015 04:33 PM)fhub Wrote:  This is one of the problems I don't really like, because you just need to put a long and complicated formula into a calculator program - simply boring.
And there's not much to 'optimize' apart from the usual tricks (using register arithmetics, complex registers etc.)

Easter programs for programmable calculators have a long tradition – exactly because they handle these long and complicated formulas. May I draw the gentlemen's attention for instance to this article: An Easter program for the HP29C.

In general, there are several ways of computing the Easter date. Gauss himself changed his formula several times. A good overview can be found in the respectice German wikipedia article. Please especially note the Lichtenberg formula at the end, as it directly includes two exceptions that else would have to be handled separately.

Dieter
11-05-2015, 02:55 PM
Post: #14
 fhub Member Posts: 188 Joined: Dec 2013
RE: Wp34s date from DOY
(11-05-2015 01:30 PM)Dieter Wrote:  Easter programs for programmable calculators have a long tradition – exactly because they handle these long and complicated formulas.
Well, I prefer short and simple formulas, e.g. calculating the Christmas date.

But seriously, since I'm atheist I'm not interested at all in any kinds of religious dates, and from a scientific point of view this Easter date is also absolutely uninteresting - it's just a 'human defined' special day of the year.

Franz
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