Re: Working with the set of real numbers (was: Finding size of Variable)

2014-03-05 Thread Steven D'Aprano
Following up on my own post. On Wed, 05 Mar 2014 07:52:01 +, Steven D'Aprano wrote: On Tue, 04 Mar 2014 23:25:37 -0500, Roy Smith wrote: I stopped paying attention to mathematicians when they tried to convince me that the sum of all natural numbers is -1/12. [...] In effect, the author

Re: Working with the set of real numbers (was: Finding size of Variable)

2014-03-05 Thread wxjmfauth
Mathematics? The Flexible String Representation is a very nice example of a mathematical absurdity. jmf PS Do not even think to expect to contradict me. Hint: sheet of paper and pencil. -- https://mail.python.org/mailman/listinfo/python-list

Re: Working with the set of real numbers (was: Finding size of Variable)

2014-03-05 Thread Oscar Benjamin
On 5 March 2014 07:52, Steven D'Aprano st...@pearwood.info wrote: On Tue, 04 Mar 2014 23:25:37 -0500, Roy Smith wrote: I stopped paying attention to mathematicians when they tried to convince me that the sum of all natural numbers is -1/12. I'm pretty sure they did not. Possibly a physicist

Re: Working with the set of real numbers (was: Finding size of Variable)

2014-03-05 Thread Steven D'Aprano
On Wed, 05 Mar 2014 12:21:37 +, Oscar Benjamin wrote: On 5 March 2014 07:52, Steven D'Aprano st...@pearwood.info wrote: On Tue, 04 Mar 2014 23:25:37 -0500, Roy Smith wrote: I stopped paying attention to mathematicians when they tried to convince me that the sum of all natural numbers is

Re: Working with the set of real numbers (was: Finding size of Variable)

2014-03-05 Thread Chris Angelico
On Thu, Mar 6, 2014 at 4:43 AM, Steven D'Aprano steve+comp.lang.pyt...@pearwood.info wrote: Physics is the fundamental science, at least according to the physicists, and Real Soon Now they'll have a Theory Of Everything, something small enough to print on a tee-shirt, which will explain

Re: Working with the set of real numbers (was: Finding size of Variable)

2014-03-05 Thread Chris Kaynor
On Wed, Mar 5, 2014 at 9:43 AM, Steven D'Aprano steve+comp.lang.pyt...@pearwood.info wrote: At one time, Euler summed an infinite series and got -1, from which he concluded that -1 was (in some sense) larger than infinity. I don't know what justification he gave, but the way I think of it is

Re: Working with the set of real numbers (was: Finding size of Variable)

2014-03-05 Thread Grant Edwards
On 2014-03-05, Chris Kaynor ckay...@zindagigames.com wrote: On Wed, Mar 5, 2014 at 9:43 AM, Steven D'Aprano steve+comp.lang.pyt...@pearwood.info wrote: At one time, Euler summed an infinite series and got -1, from which he concluded that -1 was (in some sense) larger than infinity. I don't

Re: Working with the set of real numbers (was: Finding size of Variable)

2014-03-05 Thread Oscar Benjamin
On 5 March 2014 17:43, Steven D'Aprano steve+comp.lang.pyt...@pearwood.info wrote: On Wed, 05 Mar 2014 12:21:37 +, Oscar Benjamin wrote: The argument that the sum of all natural numbers comes to -1/12 is just some kind of hoax. I don't think *anyone* seriously believes it. You would be

Re: Working with the set of real numbers (was: Finding size of Variable)

2014-03-05 Thread Roy Smith
In article 53176225$0$29987$c3e8da3$54964...@news.astraweb.com, Steven D'Aprano steve+comp.lang.pyt...@pearwood.info wrote: Physics is the fundamental science, at least according to the physicists, and Real Soon Now they'll have a Theory Of Everything, something small enough to print on a

Re: Working with the set of real numbers (was: Finding size of Variable)

2014-03-05 Thread Steven D'Aprano
On Wed, 05 Mar 2014 21:31:51 -0500, Roy Smith wrote: In article 53176225$0$29987$c3e8da3$54964...@news.astraweb.com, Steven D'Aprano steve+comp.lang.pyt...@pearwood.info wrote: Physics is the fundamental science, at least according to the physicists, and Real Soon Now they'll have a Theory

Re: Working with the set of real numbers (was: Finding size of Variable)

2014-03-05 Thread Chris Angelico
On Thu, Mar 6, 2014 at 2:06 PM, Steven D'Aprano steve+comp.lang.pyt...@pearwood.info wrote: They ask a computer programmer to adjudicate who is right, so he writes a program to print out all the primes: 1 is prime 1 is prime 1 is prime 1 is prime 1 is prime And he claimed that he was

Re: Working with the set of real numbers (was: Finding size of Variable)

2014-03-05 Thread Grant Edwards
On 2014-03-06, Roy Smith r...@panix.com wrote: In article 53176225$0$29987$c3e8da3$54964...@news.astraweb.com, Steven D'Aprano steve+comp.lang.pyt...@pearwood.info wrote: Physics is the fundamental science, at least according to the physicists, and Real Soon Now they'll have a Theory Of

Re: Working with the set of real numbers (was: Finding size of Variable)

2014-03-05 Thread Roy Smith
In article 5317e640$0$29985$c3e8da3$54964...@news.astraweb.com, Steven D'Aprano steve+comp.lang.pyt...@pearwood.info wrote: On Wed, 05 Mar 2014 21:31:51 -0500, Roy Smith wrote: In article 53176225$0$29987$c3e8da3$54964...@news.astraweb.com, Steven D'Aprano

Re: Working with the set of real numbers (was: Finding size of Variable)

2014-03-04 Thread Ian Kelly
On Mon, Mar 3, 2014 at 11:35 PM, Chris Angelico ros...@gmail.com wrote: In constant space, that will produce the sum of two infinite sequences of digits. (And it's constant time, too, except when it gets a stream of nines. Adding three thirds together will produce an infinite loop as it waits

Re: Working with the set of real numbers (was: Finding size of Variable)

2014-03-04 Thread Ian Kelly
On Tue, Mar 4, 2014 at 4:19 AM, Ian Kelly ian.g.ke...@gmail.com wrote: def cf_sqrt(n): Yield the terms of the square root of n as a continued fraction. m = 0 d = 1 a = a0 = floor_sqrt(n) while True: yield a next_m = d * a - m next_d = (n - next_m

Re: Working with the set of real numbers (was: Finding size of Variable)

2014-03-04 Thread Albert van der Horst
In article mailman.7702.1393932047.18130.python-l...@python.org, Ian Kelly ian.g.ke...@gmail.com wrote: On Mon, Mar 3, 2014 at 11:35 PM, Chris Angelico ros...@gmail.com wrote: In constant space, that will produce the sum of two infinite sequences of digits. (And it's constant time, too, except

Re: Working with the set of real numbers (was: Finding size of Variable)

2014-03-04 Thread Albert van der Horst
In article mailman.7687.1393902132.18130.python-l...@python.org, Chris Angelico ros...@gmail.com wrote: On Tue, Mar 4, 2014 at 1:45 PM, Albert van der Horst alb...@spenarnc.xs4all.nl wrote: No, the Python built-in float type works with a subset of real numbers: To be more precise: a subset of

Re: Working with the set of real numbers (was: Finding size of Variable)

2014-03-04 Thread Steven D'Aprano
On Wed, 05 Mar 2014 02:15:14 +, Albert van der Horst wrote: Adding cf's adds all computable numbers in infinite precision. However that is not even a drop in the ocean, as the computable numbers have measure zero. On the other hand, it's not really clear that the non-computable numbers

Re: Working with the set of real numbers (was: Finding size of Variable)

2014-03-04 Thread Rustom Mody
On Wednesday, March 5, 2014 9:11:13 AM UTC+5:30, Steven D'Aprano wrote: On Wed, 05 Mar 2014 02:15:14 +, Albert van der Horst wrote: Adding cf's adds all computable numbers in infinite precision. However that is not even a drop in the ocean, as the computable numbers have measure zero.

Re: Working with the set of real numbers (was: Finding size of Variable)

2014-03-04 Thread Roy Smith
In article c39d5b44-6c7b-40d1-bbb5-791a36af6...@googlegroups.com, Rustom Mody rustompm...@gmail.com wrote: I cannot find the exact quote so from memory Weyl says something to this effect: Cantor's diagonalization PROOF is not in question. Its CONCLUSION very much is. The

Re: Working with the set of real numbers (was: Finding size of Variable)

2014-03-04 Thread Steven D'Aprano
On Tue, 04 Mar 2014 23:25:37 -0500, Roy Smith wrote: I stopped paying attention to mathematicians when they tried to convince me that the sum of all natural numbers is -1/12. I'm pretty sure they did not. Possibly a physicist may have tried to tell you that, but most mathematicians consider

Re: Working with the set of real numbers (was: Finding size of Variable)

2014-03-03 Thread Albert van der Horst
In article mailman.6735.1392194885.18130.python-l...@python.org, Chris Angelico ros...@gmail.com wrote: On Wed, Feb 12, 2014 at 7:17 PM, Ben Finney ben+pyt...@benfinney.id.au wrote: Chris Angelico ros...@gmail.com writes: I have yet to find any computer that works with the set of real numbers

Re: Working with the set of real numbers (was: Finding size of Variable)

2014-03-03 Thread Chris Angelico
On Tue, Mar 4, 2014 at 1:45 PM, Albert van der Horst alb...@spenarnc.xs4all.nl wrote: No, the Python built-in float type works with a subset of real numbers: To be more precise: a subset of the rational numbers, those with a denominator that is a power of two. And no more than N bits (53 in a

Re: Working with the set of real numbers (was: Finding size of Variable)

2014-03-03 Thread Rustom Mody
On Tuesday, March 4, 2014 8:32:01 AM UTC+5:30, Chris Angelico wrote: On Tue, Mar 4, 2014 at 1:45 PM, Albert van der Horst wrote: No, the Python built-in float type works with a subset of real numbers: To be more precise: a subset of the rational numbers, those with a denominator that is a

Re: Working with the set of real numbers (was: Finding size of Variable)

2014-03-03 Thread Chris Angelico
On Tue, Mar 4, 2014 at 2:13 PM, Rustom Mody rustompm...@gmail.com wrote: But it's a far cry from all real numbers. Even allowing for continued fractions adds only some more; I don't think you can represent surds that way. See

Re: Working with the set of real numbers (was: Finding size of Variable)

2014-03-03 Thread Rustom Mody
On Tuesday, March 4, 2014 9:16:25 AM UTC+5:30, Chris Angelico wrote: On Tue, Mar 4, 2014 at 2:13 PM, Rustom Mody wrote: But it's a far cry from all real numbers. Even allowing for continued fractions adds only some more; I don't think you can represent surds that way. See

Re: Working with the set of real numbers (was: Finding size of Variable)

2014-03-03 Thread Steven D'Aprano
On Tue, 04 Mar 2014 14:46:25 +1100, Chris Angelico wrote: That's neat, didn't know that. Is there an efficient way to figure out, for any integer N, what its sqrt's CF sequence is? And what about the square roots of non-integers - can you represent √π that way? I suspect, though I can't

Re: Working with the set of real numbers (was: Finding size of Variable)

2014-03-03 Thread Chris Angelico
On Tue, Mar 4, 2014 at 4:53 PM, Steven D'Aprano st...@pearwood.info wrote: On Tue, 04 Mar 2014 14:46:25 +1100, Chris Angelico wrote: That's neat, didn't know that. Is there an efficient way to figure out, for any integer N, what its sqrt's CF sequence is? And what about the square roots of

Working with the set of real numbers (was: Finding size of Variable)

2014-02-12 Thread Ben Finney
Chris Angelico ros...@gmail.com writes: I have yet to find any computer that works with the set of real numbers in any way. Never mind optimization, they simply cannot work with real numbers. Not *any* computer? Not in *any* way? The Python built-in ‘float’ type “works with the set of real

Re: Working with the set of real numbers (was: Finding size of Variable)

2014-02-12 Thread wxjmfauth
Integers are integers. (1) Characters are characters. (2) (1) is a unique natural set. (2) is an artificial construct working with 3 sets (unicode). jmf -- https://mail.python.org/mailman/listinfo/python-list

Re: Working with the set of real numbers (was: Finding size of Variable)

2014-02-12 Thread Chris Angelico
On Wed, Feb 12, 2014 at 7:17 PM, Ben Finney ben+pyt...@benfinney.id.au wrote: Chris Angelico ros...@gmail.com writes: I have yet to find any computer that works with the set of real numbers in any way. Never mind optimization, they simply cannot work with real numbers. Not *any* computer?

Re: Working with the set of real numbers (was: Finding size of Variable)

2014-02-12 Thread wxjmfauth
Le mercredi 12 février 2014 09:35:38 UTC+1, wxjm...@gmail.com a écrit : Integers are integers. (1) Characters are characters. (2) (1) is a unique natural set. (2) is an artificial construct working with 3 sets (unicode). jmf Addendum: One should not confuse unicode and

Re: Working with the set of real numbers (was: Finding size of Variable)

2014-02-12 Thread Jussi Piitulainen
Chris Angelico writes: On Wed, Feb 12, 2014 at 7:17 PM, Ben Finney wrote: What specific behaviour would, for you, qualify as “works with the set of real numbers in any way”? Being able to represent surds, pi, e, etc, for a start. It'd theoretically be possible with an algebraic notation

Re: Working with the set of real numbers (was: Finding size of Variable)

2014-02-12 Thread Grant Edwards
On 2014-02-12, Ben Finney ben+pyt...@benfinney.id.au wrote: Chris Angelico ros...@gmail.com writes: I have yet to find any computer that works with the set of real numbers in any way. Never mind optimization, they simply cannot work with real numbers. Not *any* computer? Not in *any* way?

Re: Working with the set of real numbers (was: Finding size of Variable)

2014-02-12 Thread Gisle Vanem
Grant Edwards wrote: Not *any* computer? Not in *any* way? The Python built-in float type works with the set of real numbers, in a way. The only people who think that are people who don't actualy _use_ floating point types on computers. FPU parsing the IEEE spec, or?. I didn't quite parse