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Groups > comp.lang.forth > #57605
| From | rickman <gnuarm@gmail.com> |
|---|---|
| Newsgroups | comp.lang.forth |
| Subject | Re: real to rational number |
| Date | 2017-04-19 15:41 -0400 |
| Organization | A noiseless patient Spider |
| Message-ID | <od8ebi$531$1@dont-email.me> (permalink) |
| References | <d34926ea-ca84-4918-aa2f-82ebb21c6470@googlegroups.com> <ca01c066-3b47-4138-8ff2-558bea6d1db8@googlegroups.com> <d9c00413-adf9-4d5f-a342-2b0e436b733a@googlegroups.com> <8c2f9ac1-9fb9-4dc4-a43e-66f50ea2b838@googlegroups.com> <4203a8d4-bd7f-45c4-8552-e6c916e85ee4@googlegroups.com> |
On 4/19/2017 7:43 AM, krishna.myneni@ccreweb.org wrote: > On Wednesday, April 19, 2017 at 12:53:44 AM UTC-5, lehs wrote: >> I thought the float value represented some kind of measurement with an error, but if the float is regarded as a rational >> >> a/b=N/10^n >> >> then isn't it only to divide N and 10^n with their greatest common divisor d? >> >> a=N/d and b=10^n/d >> > > Not exactly, since the last significant digit of our value, r, is rounded. For example, try the gcd procedure with the example, > > r = 7.61904761904762e-02 > > If you attempt gcd(761904761904762, 10^17), you will get 2, and that does not give you the simple fraction. > >> If there is an intervall and a/b is known to be in this intervall one has to know more. In your case the limitations of the primes and exponents is further conditions such that not any float will have a solution at all. Or am I missunderstanding? > > You are not misunderstanding the problem. One way to visualize it is to consider the solution space as the lattice of points in the first quadrant of the Cartesian grid, with "a" taking on integer values along the y-axis, and "b" taking on the values along the x-axis. We exclude the points which fall on the y-axis, since these represent r = inf. > > Now, given the restriction, |r| = a/b <= 1, we can cut the solution space in half, by only considering those lattice points which fall along or below the diagonal, y = x. Given the value of |r|, we should be able to restrict the solution space further. > > In the 3j symbol problem, we may use problem-domain specific knowledge, when the solutions for a restricted range of quantum numbers, e.g. for j <= 4, |r| can only take on values which are a product of restricted multiples of a range of restricted primes. That reduces the search space to a finite set of lattice points; however, it is not the same as finding the rational number for arbitrary finite-precision |r|, even with the restriction |r| <= 1. I don't understand all of the language you are using, but there are an infinite number of integers and the solution can be found arbitrarily close to any real value by finding larger value integers. To my understanding there is *no* single solution unless you restrict the magnitude of the integers you use. -- Rick C
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real to rational number krishna.myneni@ccreweb.org - 2017-04-18 04:49 -0700
Re: real to rational number lehs <skydda.barnen@gmail.com> - 2017-04-18 06:48 -0700
Re: real to rational number krishna.myneni@ccreweb.org - 2017-04-18 19:09 -0700
Re: real to rational number lehs <skydda.barnen@gmail.com> - 2017-04-18 22:53 -0700
Re: real to rational number krishna.myneni@ccreweb.org - 2017-04-19 04:43 -0700
Re: real to rational number rickman <gnuarm@gmail.com> - 2017-04-19 15:41 -0400
Re: real to rational number Paul Rubin <no.email@nospam.invalid> - 2017-04-19 13:03 -0700
Re: real to rational number "Rudy Velthuis" <newsgroups@rvelthuis.de> - 2017-04-20 17:26 +0000
Re: real to rational number hughaguilar96@gmail.com - 2017-04-20 14:29 -0700
Re: real to rational number "Rudy Velthuis" <newsgroups@rvelthuis.de> - 2017-04-19 23:44 +0000
Re: real to rational number Paul Rubin <no.email@nospam.invalid> - 2017-04-19 19:30 -0700
Re: real to rational number "Rudy Velthuis" <newsgroups@rvelthuis.de> - 2017-04-20 17:08 +0000
Re: real to rational number Paul Rubin <no.email@nospam.invalid> - 2017-04-20 11:46 -0700
Re: real to rational number "Rudy Velthuis" <newsgroups@rvelthuis.de> - 2017-04-21 09:47 +0000
Re: real to rational number lehs <skydda.barnen@gmail.com> - 2017-04-20 20:49 -0700
Re: real to rational number rickman <gnuarm@gmail.com> - 2017-04-19 15:36 -0400
Re: real to rational number krishna.myneni@ccreweb.org - 2017-04-20 18:44 -0700
Re: real to rational number hughaguilar96@gmail.com - 2017-04-18 07:06 -0700
Re: real to rational number krishna.myneni@ccreweb.org - 2017-04-18 19:17 -0700
Re: real to rational number Paul Rubin <no.email@nospam.invalid> - 2017-04-18 19:45 -0700
Re: real to rational number krishna.myneni@ccreweb.org - 2017-04-18 19:57 -0700
Re: real to rational number anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2017-04-19 05:35 +0000
Re: real to rational number hughaguilar96@gmail.com - 2017-04-18 23:42 -0700
Re: real to rational number krishna.myneni@ccreweb.org - 2017-04-19 04:53 -0700
Re: real to rational number hughaguilar96@gmail.com - 2017-04-19 11:32 -0700
Re: real to rational number minforth@arcor.de - 2017-04-18 08:23 -0700
Re: real to rational number krishna.myneni@ccreweb.org - 2017-04-18 19:24 -0700
Re: real to rational number Paul Rubin <no.email@nospam.invalid> - 2017-04-18 19:48 -0700
Re: real to rational number krishna.myneni@ccreweb.org - 2017-04-18 20:01 -0700
Re: real to rational number Paul Rubin <no.email@nospam.invalid> - 2017-04-18 19:39 -0700
Re: real to rational number krishna.myneni@ccreweb.org - 2017-04-18 19:56 -0700
Re: real to rational number Paul Rubin <no.email@nospam.invalid> - 2017-04-19 00:41 -0700
Re: real to rational number krishna.myneni@ccreweb.org - 2017-04-19 04:48 -0700
Re: real to rational number hughaguilar96@gmail.com - 2017-04-19 11:30 -0700
Re: real to rational number albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2017-04-20 20:15 +0200
Re: real to rational number krishna.myneni@ccreweb.org - 2017-04-20 15:23 -0700
Re: real to rational number Paul Rubin <no.email@nospam.invalid> - 2017-04-20 18:52 -0700
Re: real to rational number Pablo Hugo Reda <pabloreda@gmail.com> - 2017-04-18 19:58 -0700
Re: real to rational number krishna.myneni@ccreweb.org - 2017-04-18 20:05 -0700
Re: real to rational number Pablo Hugo Reda <pabloreda@gmail.com> - 2017-04-19 05:30 -0700
Re: real to rational number Pablo Hugo Reda <pabloreda@gmail.com> - 2017-04-19 05:35 -0700
Re: real to rational number Pablo Hugo Reda <pabloreda@gmail.com> - 2017-04-19 05:41 -0700
Re: real to rational number krishna.myneni@ccreweb.org - 2017-04-19 19:39 -0700
Re: real to rational number "Rudy Velthuis" <newsgroups@rvelthuis.de> - 2017-04-19 23:16 +0000
Re: real to rational number krishna.myneni@ccreweb.org - 2017-04-19 19:42 -0700
Re: real to rational number "Rudy Velthuis" <newsgroups@rvelthuis.de> - 2017-04-20 17:15 +0000
Re: real to rational number krishna.myneni@ccreweb.org - 2017-04-20 15:11 -0700
Re: real to rational number hughaguilar96@gmail.com - 2017-04-20 15:49 -0700
Re: real to rational number Alex <alex@rivadpm.com> - 2017-04-21 00:20 +0100
Re: real to rational number krishna.myneni@ccreweb.org - 2017-04-20 18:49 -0700
Re: real to rational number The Beez <the.beez.speaks@gmail.com> - 2017-04-21 03:18 -0700
Re: real to rational number krishna.myneni@ccreweb.org - 2017-04-21 18:39 -0700
Re: real to rational number krishna.myneni@ccreweb.org - 2017-04-21 18:46 -0700
Re: real to rational number Paul Rubin <no.email@nospam.invalid> - 2017-04-21 21:55 -0700
Re: real to rational number krishna.myneni@ccreweb.org - 2017-04-22 08:33 -0700
Re: real to rational number Paul Rubin <no.email@nospam.invalid> - 2017-04-22 13:35 -0700
Re: real to rational number The Beez <the.beez.speaks@gmail.com> - 2017-04-24 00:58 -0700
Re: real to rational number minforth@arcor.de - 2017-04-24 01:08 -0700
Re: real to rational number minforth@arcor.de - 2017-04-23 02:28 -0700
Re: real to rational number hughaguilar96@gmail.com - 2017-04-21 18:43 -0700
rationalising reality, was Re: real to rational number Jan Coombs <jenfhaomndgfwutc@murmic.plus.com> - 2017-04-22 10:28 +0100
Re: rationalising reality, was Re: real to rational number Mark Wills <markwills1970@gmail.com> - 2017-04-22 02:33 -0700
Re: real to rational number krishna.myneni@ccreweb.org - 2017-04-20 16:22 -0700
Re: real to rational number hughaguilar96@gmail.com - 2017-04-20 22:02 -0700
Re: real to rational number Julian Fondren <julian.fondren@gmail.com> - 2017-04-21 00:12 -0700
Re: real to rational number "Rudy Velthuis" <newsgroups@rvelthuis.de> - 2017-04-21 09:55 +0000
Re: real to rational number hughaguilar96@gmail.com - 2017-04-25 10:52 -0700
Re: real to rational number "Rudy Velthuis" <newsgroups@rvelthuis.de> - 2017-04-29 03:16 +0000
Re: real to rational number "Rudy Velthuis" <newsgroups@rvelthuis.de> - 2017-04-21 09:52 +0000
Re: real to rational number lehs <skydda.barnen@gmail.com> - 2017-04-21 05:35 -0700
Re: real to rational number hughaguilar96@gmail.com - 2017-04-21 19:05 -0700
Re: real to rational number The Beez <the.beez.speaks@gmail.com> - 2017-04-24 01:14 -0700
Re: real to rational number Cecil Bayona <cbayona@cbayona.com> - 2017-04-24 11:31 -0500
Re: real to rational number The Beez <the.beez.speaks@gmail.com> - 2017-04-25 00:52 -0700
Re: real to rational number hughaguilar96@gmail.com - 2017-04-24 11:43 -0700
Re: real to rational number The Beez <the.beez.speaks@gmail.com> - 2017-04-25 00:35 -0700
Re: real to rational number The Beez <the.beez.speaks@gmail.com> - 2017-04-25 01:09 -0700
Re: real to rational number minforth@arcor.de - 2017-04-26 01:55 -0700
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