Load of bollocks
Date/time format is a human convention - so it doesn't mean a thing.
Pi(e) Day of the Century is upon us! Time to celebrate 3/14/15 in style, surely?
It's the 14th of March, which means only one thing to maths nerds in the good ol' US of A: Pi Day. Americans, who insist on putting the month before the day (crazy, right?) when it comes to date arrangement, celebrate the mathematical constant that frames our science and maths – 3/14. It also happens to be Albert Einstein's …
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Saturday 14th March 2015 15:34 GMT Brent Longborough
Every year, the same B*ll*x
Thank you so much for irritating me this Saturday.
Everyone with an IQ over 75 already knows this is the stupidest meme-that-doesn't-work ever invented; as to the remainder, can we try to convince our North American colleagues that 31st April would be a better date for this nonsense?
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Saturday 14th March 2015 21:41 GMT phil dude
fixed that for you....
bc -l
bc 1.06.95
Copyright 1991-1994, 1997, 1998, 2000, 2004, 2006 Free Software Foundation, Inc.
This is free software with ABSOLUTELY NO WARRANTY.
For details type `warranty'.
scale=100
4*a(1)
3.141592653589793238462643383279502884197169399375105820974944592307\
8164062862089986280348253421170676
P.
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Monday 16th March 2015 06:45 GMT the spectacularly refined chap
Re: I must be using biblical linux
Define the mathlib with '-l' (man bc).
No, the problem there isn't that the maths library isn't loaded but the scale factor is left at default (i.e. integer). You need to set the scale register to some positive value to get that many decimal places. This is a backstop against recurring decimals and irrational numbers - since it is arbitrary precison even something as simple as 1/3 would carry on forever as it tries to calculate an exact decimal value (0.333333...) unless some limit was in place. See the very man page you reference.
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Saturday 14th March 2015 16:20 GMT VinceH
"Americans, who insist on putting the month before the day (crazy, right?) when it comes to date arrangement, celebrate the mathematical constant that frames our science and maths – 3/14."
As I tweeted this morning:
Today is Pi Day. The date corresponds with Pi, the ratio of a circle's circumference to its diameter* - which is now 14.315 due to inflation.
* Actually, I didn't spot until much later that I actually said "the ratio of a circle's circumference to its ratio" - D'oh!
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Saturday 14th March 2015 17:11 GMT Anonymous Coward
Americans and PI
Although there is an urban myth dating from 1998 that Alabama legislated Pi to be 3 which was based on an April fool which went viral
see http://www.snopes.com/media/notnews/pi.asp
The amazing thing is that something similar did in fact happen a century earlier in Indiana where House Bill 246 was passed which define PI as 3.2
see
https://www.agecon.purdue.edu/crd/localgov/Second%20Level%20pages/indiana_pi_bill.htm
Fortunately the bill died in the senate after the vote was indefinitely postponed
http://mentalfloss.com/article/30214/new-math-time-indiana-tried-change-pi-32
http://io9.com/5880792/the-eccentric-crank-who-tried-to-legislate-the-value-of-pi
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Sunday 15th March 2015 10:34 GMT Adrian Harvey
Re: Americans and PI
I took an engineering course where we used 3 as the value for pi.
Admittedly this was because the gearboxes on the lathes only had a limited set of speeds on offer, so there was no point at all in using more than 1 significant figure. Still 3 is not wrong for pi so long as you only want results with limited precision!
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Saturday 14th March 2015 18:13 GMT John Brown (no body)
9:26?
3.14152126? Or do mathematicians still use a 12 hour clock? Time and date calculations are fraught with enough complications with doing that.
Surely if we are going to be dropping centuries, removing leading zeros and swapping the locations of mm and dd then it ought be at 9:26AM
Maybe it should be 31/4/15 9:26 , ie 2031, April 15th.
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Saturday 14th March 2015 20:53 GMT Anonymous Coward
"[...] format other than YYMMDD HH:MM:SS is illogical?"
The generic expression is usually? written as YYYY/MM/DD HH:MM:SS
Unless you are using filenames that take a slash and : as delimiters in which case YYYYMMDD HHMMSS is the best form for any sorted activity.
An abbreviated YY year has led to all sorts of complications - like old people being sent their school joining instructions because they have reached 105. Since the millennium it has also been a source of confusion as to which end is the year field.
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Monday 16th March 2015 00:17 GMT Anonymous Coward
> An abbreviated YY year has led to all sorts of complications
This is a pet peeve of mine.
Database programmers (and UI designers) are forever being caught out with ambiguous date formats.
What I can't fathom is why we still insist on stupid date formats on web pages and on forms like 01/02/03 when an unambiguous form is just as straighforward and less likely to lead to mistakes, especially after the Y2K fiasco.
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Sunday 15th March 2015 08:19 GMT Ken Moorhouse
Surely any date/time format other than YYMMDD HH:MM:SS is illogical?
Only in a universe where the earth is at its centre.
I presumed that this was a tongue-in-cheek comment, but with 4 upvotes I think this kind of thing needs to be seriously debunked.
YYMMDD HH:MM:SS does not reference a unique point in time. Not unless you state a timezone and also the underlying calendar. Don't forget that with western cultures there have been calendars other than the current one. Even then, unless you are very careful, some times are not unique. For example, in areas with Daylight Saving Time, when the clocks go back, the same time can exist twice. (And that is all without bringing non-western calendars into consideration).
Pi, on the other hand, is a constant. It is constant whatever your units of measure. Ok, ok, to be as pedantic as I have been the number base (10) needs to be mentioned.
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Saturday 14th March 2015 22:13 GMT raving angry loony
Correction...
Shouldn't that be "time to celebrate American Pi"? Seeing as the date convention required for this to work is one that's used by the USA and, I believe, Belize. That's it. It's only seen in Canada because it's so dominated by American corporations, but it's not actually a standard in Canada at all. So yeah, "American Pi". Enjoy.
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Sunday 15th March 2015 07:57 GMT Bill Gray
Oh, lighten up already!
Yes, it's a silly idea. Yes, month/day/year is silly (I say as a Yank; as an astronomer, I think YYYY/MM/DD is the only sensible way to go). However, observing Pi Day gives me an opportunity to indoctrinate my 8-year old daughter in her cultural heritage as a budding math nerd, and I can usually persuade my wife to make a pie in celebration. I have no qualms about double-dipping and making use of DD/MM ordering to celebrate 22/7 as Pi Approximation Day, observed with a not-pie-like dish such as a quiche.
I understand the joy of bashing Yanks, and there are many good reasons to do so (insert comments involving beer, politics, and spelling here). This, I submit, is not one of them.
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Sunday 15th March 2015 10:44 GMT John H Woods
Re: Oh, lighten up already!
Love the pie approximation idea, that is utterly brilliant (although the corollary is that the interval in which you can eat an actual pie is infinitesimally short).
The Yank-bashing in this thread is just a bit of light-hearted nerdy banter, which - in this case - is richly deserved. First line of www.piday.org says: "Pi Day is celebrated on March 14th (3/14) around the world"
Get them to change that to in the USA and Belize and you might have a point :-)
Seriously, tho[ugh], American nerds should campaign for that date format to be abolished, just as European nerds should for DD/MM/YYYY: these formats are effectively ambiguous for 36.2% of the time!
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Monday 16th March 2015 10:59 GMT Anonymous Coward
Re: Oh, lighten up already!
" This, I submit, is not one of them."
It is however one which can lead to genuine confusion that matters. The possibility of USA format dates in a screen-scraping trawl of web sites slows it down considerably.
The algorithm needs human intervention for any date with day/month fields that both have values <= 12. As some US sites do not use the USA format then the country of origin cannot be used as a tie-breaker. Similarly other countries' sites advertising USA tours may give the dates in USA format.
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Sunday 15th March 2015 19:19 GMT harmjschoonhoven
The proper value of pi
From Notes by an Oxford Chiel by Lewis Carroll, The new method of evaluation as applied to π.
In the early treatizes on this subject, the mean value assigned to π will be found to be 40.000000. Later writers suspected that the decimal point had been accidentally shifted, and that the proper value was 400.00000.
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Monday 16th March 2015 12:28 GMT John H Woods
Re: Rounding down from "9"
"Bankers Rounding dictates that you round to the nearest even number" -- Ken Moorhouse
Pretty sure that's not quite right ... 2.9 does not get rounded to 2, surely? I think you only round to the nearest even when you are at exactly 0.5, i.e. 2.5 is 2 and so is 1.5. My maths is rusty but I think that means that you can never use the rule when rounding a irrational number.
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Biting the hand that feeds IT
