Maths constants
in [Fortran]
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From: Les Neilson on 20 Jan 2010 09:29 "Gordon Sande" <g.sande(a)worldnet.att.net> wrote in message news:2010012009513416807-gsande(a)worldnetattnet... > On 2010-01-20 06:42:25 -0400, "Les Neilson" <l.neilson(a)nospam.co.uk> said: > >> >> "Simon Geard" <simon(a)whiteowl.co.uk> wrote in message >> news:hj6krv$nj0$1(a)news.eternal-september.org... >>> On 19/01/2010 20:31, Richard Maine wrote: >> <snip> >>> >>> Which makes me wonder why there aren't intrinsic parameters to go with >>> intrinsic functions. Presumably they have been suggested for possible >>> inclusion in f90, 95, 2003 and 2008 but rejected. >>> >>> Simon >> >> The first difficulty would be specifying a *finite* list of constants >> (there are rather a lot across the sciences that I can think of and >> presumably plenty more of which I am unaware or have forgotten - >> someone's favourite constant being left out might cause a diplomatic >> incident!) >> >> Then there are those constants which are continually being refined to >> greater accuracy. > > When was the last time that the value of the mathematical constant pi was > changed? > Or any other mathematical constant for that matter. > Well to be silly - Only recently. From the BBC website (6th Jan 2010) : "A computer scientist claims to have computed the mathematical constant pi to nearly 2.7 trillion digits, some 123 billion more than the previous record. Fabrice Bellard used a desktop computer to perform the calculation, taking a total of 131 days to complete and check the result. This version of pi takes over a terabyte of hard disk space to store." Admittedly the concept is precision and we don't yet have general purpose pcs with the memory to store the real(1_TB), parameter pi = <insert new value here> Some constants have an internationally agreed fixed value but others are being tested experimentally every day and the error bar(s) may be revised any time. But I was only trying to point out that 10 people would come up with 11 lists of their required "constants". :-) Les
From: Gordon Sande on 20 Jan 2010 09:31 On 2010-01-20 10:11:21 -0400, user1 <user1(a)example.net> said: > Gordon Sande wrote: > >> >> When was the last time that the value of the mathematical constant pi >> was changed? > > Indiana House Bill No. 246, 1897 > > unsuccessful? Thank you for the careful snipping to confuse the issue of the mathematical value with the legal value for real esate frontage calculation. You lack of context for the law indictes a failure to understand its purpose. Good laugh but misses the point or perhaps it illustrates some other point. You still have not given an example of a changing mathematical constant.
From: Gordon Sande on 20 Jan 2010 09:41 On 2010-01-20 10:29:53 -0400, "Les Neilson" <l.neilson(a)nospam.co.uk> said: > > "Gordon Sande" <g.sande(a)worldnet.att.net> wrote in message > news:2010012009513416807-gsande(a)worldnetattnet... >> On 2010-01-20 06:42:25 -0400, "Les Neilson" <l.neilson(a)nospam.co.uk> said: >> >>> >>> "Simon Geard" <simon(a)whiteowl.co.uk> wrote in message >>> news:hj6krv$nj0$1(a)news.eternal-september.org... >>>> On 19/01/2010 20:31, Richard Maine wrote: >>> <snip> >>>> >>>> Which makes me wonder why there aren't intrinsic parameters to go with >>>> intrinsic functions. Presumably they have been suggested for possible >>>> inclusion in f90, 95, 2003 and 2008 but rejected. >>>> >>>> Simon >>> >>> The first difficulty would be specifying a *finite* list of constants >>> (there are rather a lot across the sciences that I can think of and >>> presumably plenty more of which I am unaware or have forgotten - >>> someone's favourite constant being left out might cause a diplomatic >>> incident!) >>> >>> Then there are those constants which are continually being refined to >>> greater accuracy. >> >> When was the last time that the value of the mathematical constant pi >> was changed? >> Or any other mathematical constant for that matter. >> > > Well to be silly - Only recently. > > From the BBC website (6th Jan 2010) : > "A computer scientist claims to have computed the mathematical constant > pi to nearly 2.7 trillion digits, some 123 billion more than the > previous record. Fabrice Bellard used a desktop computer to perform the > calculation, taking a total of 131 days to complete and check the > result. This version of pi takes over a terabyte of hard disk space to > store." But a formulae for the n'th (for any n) hex digit of pi has been well known for a long time. A corresponding formulae for other bases is lacking and base conversion can be a drag. But most computers are happy with binary so conversion is not an issue except when you want to read it. So I fail to see why you are concerned or even see this amusing exercise as very interesting. ;-) > Admittedly the concept is precision and we don't yet have general > purpose pcs with the memory to store the > real(1_TB), parameter pi = <insert new value here> > > Some constants have an internationally agreed fixed value but others > are being tested experimentally every day and the error bar(s) may be > revised any time. Are those MATHEMATICAL constants? > But I was only trying to point out that 10 people would come up with 11 > lists of their required "constants". It only takes two economists to offer three opinions. That's efficiency! Some are even capapble of offering two opinions. "And on the other hand." One armed economists are in great demand becuase of this. ;-) > :-) > > Les
From: Michel Olagnon on 20 Jan 2010 10:54 Les Neilson wrote: > > But I was only trying to point out that 10 people would come up with 11 > lists of their required "constants". > > :-) > Can't you merge those 110 lists ? :-)
From: user1 on 20 Jan 2010 11:02
Gordon Sande wrote: > On 2010-01-20 10:11:21 -0400, user1 <user1(a)example.net> said: > >> Gordon Sande wrote: >> >>> >>> When was the last time that the value of the mathematical constant pi >>> was changed? >> >> Indiana House Bill No. 246, 1897 >> >> unsuccessful? > > Thank you for the careful snipping to confuse the issue of the mathematical > value with the legal value for real esate frontage calculation. You lack > of context for the law indictes a failure to understand its purpose. Good > laugh but misses the point or perhaps it illustrates some other point. > > You still have not given an example of a changing mathematical constant. > I have always been under the impression that the legislators at the time thought that they could in fact change the value of a mathematical constant. |