Re: Hack request: rational numbers

2007-10-26 Thread Anton Mellit
> Hi! > > I am using rational numbers from the gmpy module and I find that creating > one in Python using > >>>> mpq(3,4) > > is rather clumsy. Clearly, minimal representation of this rational number > is > >3/4 > > but in Python this expres

Re: Rational numbers

2007-04-27 Thread M.-A. Lemburg
On 2007-02-23 16:35, Martin Manns wrote: > Hi, > > I am starting to use rationals and since I found no batteries included, > I tried out the mxNumber package. > > However, I get strange warnings on comparison operations > (which however seem to yield correct results): > > --- > $ python > Python

Re: Rational numbers

2007-02-28 Thread Fernando Perez
[EMAIL PROTECTED] wrote: > On Feb 25, 3:09 pm, Fernando Perez <[EMAIL PROTECTED]> wrote: >> Alex, have you had a look at SAGE? >> >> http://modular.math.washington.edu/sage/ >> >> it uses GMP extensively, so they've had to patch it to work around these >> issues. You can look at the SAGE release

Re: Rational numbers

2007-02-26 Thread aleaxit
On Feb 25, 3:09 pm, Fernando Perez <[EMAIL PROTECTED]> wrote: > [EMAIL PROTECTED] wrote: > > gmpy itself is or should be pretty trivial to build on any platform > > (and I'll always happily accept any fixes that make it better on any > > specific platform, since it's easy to make them conditional s

Re: Rational numbers

2007-02-25 Thread Gabriel Genellina
En Sat, 24 Feb 2007 01:42:00 -0300, Martin Manns <[EMAIL PROTECTED]> escribió: > On Fri, 23 Feb 2007 20:20:12 -0300 > "Gabriel Genellina" <[EMAIL PROTECTED]> wrote: > >> mx.Number.Rational is horribly broken. They break this rule: >> a==b => hash(a)==hash(b) >> so they can'b be used as dictionary

Re: Rational numbers

2007-02-25 Thread Fernando Perez
[EMAIL PROTECTED] wrote: > gmpy itself is or should be pretty trivial to build on any platform > (and I'll always happily accept any fixes that make it better on any > specific platform, since it's easy to make them conditional so they'll > apply to that platform only), but the underlying GMP is

Re: Rational numbers

2007-02-25 Thread aleaxit
On Feb 24, 12:25 am, Toby A Inkster <[EMAIL PROTECTED]> wrote: > aleaxit wrote: > > If anybody who has easy access to Microsoft's MSVC++.NET (and is willing > > to try building GMP 4.2 with/for it), or a PPC Mac with XCode installed > > (possibly with MacOSX 10.3...) > > I'm writing this message on

Re: Rational numbers

2007-02-24 Thread Toby A Inkster
aleaxit wrote: > If anybody who has easy access to Microsoft's MSVC++.NET (and is willing > to try building GMP 4.2 with/for it), or a PPC Mac with XCode installed > (possibly with MacOSX 10.3...) I'm writing this message on a MacOS 10.3.9 box with Xcode 1.5 (gcc 3.3) installed. If you tell me ho

Re: Rational numbers

2007-02-23 Thread Martin Manns
On 23 Feb 2007 22:19:30 -0800 [EMAIL PROTECTED] wrote: > > Looks pretty much the same as mx.Number > > > > Does this warning come up from gmp? Do I have to compile it with > > different flags? > > Or do both wrappers use the same code? > > > > I would like to encourage the python community (i.e. t

Re: Rational numbers

2007-02-23 Thread casevh
> Looks pretty much the same as mx.Number > > Does this warning come up from gmp? Do I have to compile it with > different flags? > Or do both wrappers use the same code? > > I would like to encourage the python community (i.e. the guys > maintaining the python docs) to point out a recommended rati

Re: Rational numbers

2007-02-23 Thread Martin Manns
On Fri, 23 Feb 2007 20:20:12 -0300 "Gabriel Genellina" <[EMAIL PROTECTED]> wrote: > En Fri, 23 Feb 2007 12:35:19 -0300, Martin Manns <[EMAIL PROTECTED]> > escribió: > > > I am starting to use rationals and since I found no batteries > > included, I tried out the mxNumber package. > > > > However,

Re: Rational numbers

2007-02-23 Thread aleaxit
On Feb 23, 3:44 pm, [EMAIL PROTECTED] wrote: ... > I can keep building gmpy for Windows. I actually use MINGW since > getting GMP compiled under MSVC is "challanging". I should be able to > build new binaries for Windows this weekend. And I would be happy to > point everyone to a real release.

Re: Rational numbers

2007-02-23 Thread casevh
On Feb 23, 3:27 pm, [EMAIL PROTECTED] wrote: > On Feb 23, 12:00 pm, [EMAIL PROTECTED] wrote: >... > > > > > + gmpy is looking pretty unmaintained (dead) to me (newest update of > > > > cvs 10 months ago). > > > I worked withAlex Martelli(gmpy's maintainer) to fix a bug found by > > mensanator.

Re: Rational numbers

2007-02-23 Thread aleaxit
On Feb 23, 2:52 pm, [EMAIL PROTECTED] wrote: > > Am I hallucinating? Didn't I see at least some version > > of gmpy for Python 2.5 on SourceForge awhile back? > > I distinctly remember thinking that I don't have to > > direct people to your site, but SourceForge is not > > showing anything beyond v

Re: Rational numbers

2007-02-23 Thread aleaxit
On Feb 23, 12:00 pm, [EMAIL PROTECTED] wrote: ... > > > + gmpy is looking pretty unmaintained (dead) to me (newest update of > > > cvs 10 months ago). > > I worked withAlex Martelli(gmpy's maintainer) to fix a bug found by > mensanator. With Alex's permission, I released it as gmpy 1.04a. Alex >

Re: Rational numbers

2007-02-23 Thread Gabriel Genellina
En Fri, 23 Feb 2007 12:35:19 -0300, Martin Manns <[EMAIL PROTECTED]> escribió: > I am starting to use rationals and since I found no batteries included, > I tried out the mxNumber package. > > However, I get strange warnings on comparison operations > (which however seem to yield correct results):

Re: Rational numbers

2007-02-23 Thread casevh
> Am I hallucinating? Didn't I see at least some version > of gmpy for Python 2.5 on SourceForge awhile back? > I distinctly remember thinking that I don't have to > direct people to your site, but SourceForge is not > showing anything beyond vesion 1.01 for Python 2.4. Alex released versions 1.0

Re: Rational numbers

2007-02-23 Thread [EMAIL PROTECTED]
On Feb 23, 2:00 pm, [EMAIL PROTECTED] wrote: > On Feb 23, 10:34 am, "[EMAIL PROTECTED]" <[EMAIL PROTECTED]> wrote: > > > > > > > On Feb 23, 10:39 am, Martin Manns <[EMAIL PROTECTED]> wrote: > > > > On Fri, 23 Feb 2007 09:52:06 -0600 > > > > Larry Bates <[EMAIL PROTECTED]> wrote: > > > > I quick sea

Re: Rational numbers

2007-02-23 Thread Martin Manns
On 23 Feb 2007 12:00:10 -0800 [EMAIL PROTECTED] wrote: > > I worked with Alex Martelli (gmpy's maintainer) to fix a bug found by > mensanator. With Alex's permission, I released it as gmpy 1.04a. Alex > has not updated cvs with the fix. > > gmpy 1.04a compiles cleanly with the latest releases of

Re: Rational numbers

2007-02-23 Thread casevh
On Feb 23, 10:34 am, "[EMAIL PROTECTED]" <[EMAIL PROTECTED]> wrote: > On Feb 23, 10:39 am, Martin Manns <[EMAIL PROTECTED]> wrote: > > > On Fri, 23 Feb 2007 09:52:06 -0600 > > > Larry Bates <[EMAIL PROTECTED]> wrote: > > > I quick search of Google turned up: > > > >http://books.google.com/books?id=

Re: Rational numbers

2007-02-23 Thread Marc 'BlackJack' Rintsch
In <[EMAIL PROTECTED]>, Martin Manns wrote: > + gmpy is looking pretty unmaintained (dead) to me (newest update of > cvs 10 months ago). What CSV activities do you expect? This package seems to be pretty stable. As long as there is no bug or incompatible changes in the underlying library I woul

Re: Rational numbers

2007-02-23 Thread [EMAIL PROTECTED]
On Feb 23, 10:39 am, Martin Manns <[EMAIL PROTECTED]> wrote: > On Fri, 23 Feb 2007 09:52:06 -0600 > > Larry Bates <[EMAIL PROTECTED]> wrote: > > I quick search of Google turned up: > > >http://books.google.com/books?id=1Shx_VXS6ioC&pg=PA625&lpg=PA625&dq=p... > >http://calcrpnpy.sourceforge.net/clnu

Re: Rational numbers

2007-02-23 Thread bearophileHUGS
Martin Manns: > + gmpy is looking pretty unmaintained (dead) to me (newest update of > cvs 10 months ago). I have used it on Py2.5, so it seems to work anyway, and it's fast enough for my purposes. And probably soon some alex-shaped life will show up elsewhere. Bye, bearophile -- http://mail.py

Re: Rational numbers / alternatives to mxNumber

2007-02-23 Thread Martin Manns
On Fri, 23 Feb 2007 11:39:11 -0500 Martin Manns <[EMAIL PROTECTED]> wrote: > + boost indeed is a quite nice C++ library. However, I fear that I > would end up writing the python wrappers for operators (+ - * / min > max cmp etc.) myself. I would like to avoid this since these operators > should wo

Re: Rational numbers

2007-02-23 Thread Martin Manns
On Fri, 23 Feb 2007 09:52:06 -0600 Larry Bates <[EMAIL PROTECTED]> wrote: > I quick search of Google turned up: > > http://books.google.com/books?id=1Shx_VXS6ioC&pg=PA625&lpg=PA625&dq=python+rational+number+library&source=web&ots=BA8_4EXdQ4&sig=aDEnYA99ssKe7PSweVNyi8cS2eg > http://calcrpnpy.source

Re: Rational numbers

2007-02-23 Thread Larry Bates
Martin Manns wrote: > Hi, > > I am starting to use rationals and since I found no batteries included, > I tried out the mxNumber package. > > However, I get strange warnings on comparison operations > (which however seem to yield correct results): > > --- > $ python > Python 2.4.3 (#1, Jan 15 20

Rational numbers

2007-02-23 Thread Martin Manns
Hi, I am starting to use rationals and since I found no batteries included, I tried out the mxNumber package. However, I get strange warnings on comparison operations (which however seem to yield correct results): --- $ python Python 2.4.3 (#1, Jan 15 2007, 15:46:19) [GCC 4.1.1 (Gentoo 4.1.1-r3

Fixed-point [was Re: Rational Numbers]

2007-01-14 Thread Nick Maclaren
In article <[EMAIL PROTECTED]>, "Hendrik van Rooyen" <[EMAIL PROTECTED]> writes: |> |> Ok I will throw in a skewed ball at this point - use integer arithmetic, |> and work in tenths of cents or pennies or whatever, and don't be too |> lazy to do your own print formatting... If anyone is interes

Re: Rational Numbers

2007-01-14 Thread Nick Maclaren
In article <[EMAIL PROTECTED]>, "Hendrik van Rooyen" <[EMAIL PROTECTED]> writes: |> |> > Financial calculations need decimal FIXED-point, with a precisely |> > specified precision. It is claimed that decimal FLOATING-point |> > helps with providing that, but that claim is extremely dubious. |> >

Re: Rational Numbers

2007-01-13 Thread Hendrik van Rooyen
From: "Nick Maclaren" <[EMAIL PROTECTED]> wrote: > Financial calculations need decimal FIXED-point, with a precisely > specified precision. It is claimed that decimal FLOATING-point > helps with providing that, but that claim is extremely dubious. > I can explain the problem in as much detail as

Re: Rational Numbers

2007-01-13 Thread Nick Maclaren
In article <[EMAIL PROTECTED]>, "Simon Brunning" <[EMAIL PROTECTED]> writes: |> > |> > Financial calculations need decimal FIXED-point, with a precisely |> > specified precision. It is claimed that decimal FLOATING-point |> > helps with providing that, but that claim is extremely dubious. |> > I

Re: Rational Numbers

2007-01-13 Thread Nick Maclaren
In article <[EMAIL PROTECTED]>, Steven D'Aprano <[EMAIL PROTECTED]> writes: |> > |> > Some of the algebraic languages. (2/3)^(1/5) is held as such and |> > manipulated appropriately. |> > |> > Yes, I know that's "cheating" :-) |> |> I see your smiley, and I still don't understand. Why on earth

Re: Rational Numbers

2007-01-12 Thread Steven D'Aprano
On Fri, 12 Jan 2007 17:15:56 +, Nick Maclaren wrote: > In article <[EMAIL PROTECTED]>, > Facundo Batista <[EMAIL PROTECTED]> writes: > |> Noud Aldenhoven wrote: > |> > |> > There are a (small) couple of other issues where rational numbers could >

Re: Rational Numbers

2007-01-12 Thread Steven D'Aprano
On Fri, 12 Jan 2007 20:07:04 +, Simon Brunning wrote: > On 1/12/07, Thomas Ploch <[EMAIL PROTECTED]> wrote: >> Do not forget: >> >> - Time >> - Personal Data (like birthdays, age) > > The datetime module has perfectly good classes for holding date and > time values, and age sounds like an int

Re: Rational Numbers

2007-01-12 Thread Simon Brunning
On 1/12/07, Thomas Ploch <[EMAIL PROTECTED]> wrote: > Do not forget: > > - Time > - Personal Data (like birthdays, age) The datetime module has perfectly good classes for holding date and time values, and age sounds like an integer to me. -- Cheers, Simon B [EMAIL PROTECTED] -- http://mail.pyth

Re: Rational Numbers

2007-01-12 Thread Simon Brunning
On 12 Jan 2007 19:41:52 GMT, Nick Maclaren <[EMAIL PROTECTED]> wrote: > Sigh. I was hoping not to have that myth perpetrated again. > > Financial calculations need decimal FIXED-point, with a precisely > specified precision. It is claimed that decimal FLOATING-point > helps with providing that, b

Re: Rational Numbers

2007-01-12 Thread Thomas Ploch
Simon Brunning schrieb: > On 12 Jan 2007 15:55:39 GMT, Nick Maclaren <[EMAIL PROTECTED]> wrote: >> In article <[EMAIL PROTECTED]>, >> Carsten Haese <[EMAIL PROTECTED]> writes: >> |> but there are more use >> |> cases for Decimal than for Rational. >> >> That is dubious, but let's not start that one

Re: Rational Numbers

2007-01-12 Thread Nick Maclaren
In article <[EMAIL PROTECTED]>, "Simon Brunning" <[EMAIL PROTECTED]> writes: |> |> > |> but there are more use |> > |> cases for Decimal than for Rational. |> > |> > That is dubious, but let's not start that one again. |> |> Decimals are good for holding financial values. There's a whole lot of |

Re: Rational Numbers

2007-01-12 Thread Simon Brunning
On 12 Jan 2007 15:55:39 GMT, Nick Maclaren <[EMAIL PROTECTED]> wrote: > > In article <[EMAIL PROTECTED]>, > Carsten Haese <[EMAIL PROTECTED]> writes: > |> but there are more use > |> cases for Decimal than for Rational. > > That is dubious, but let's not start that one again. Decimals are good for

Re: Rational Numbers

2007-01-12 Thread Noud Aldenhoven
On 1/12/07, Facundo Batista <[EMAIL PROTECTED]> wrote: Noud Aldenhoven wrote: > There are a (small) couple of other issues where rational numbers could be > handy. That's because rational numbers are exact, irrational numbers (in > python) aren't. But these issues are

Re: Rational Numbers

2007-01-12 Thread Nick Maclaren
In article <[EMAIL PROTECTED]>, Facundo Batista <[EMAIL PROTECTED]> writes: |> Noud Aldenhoven wrote: |> |> > There are a (small) couple of other issues where rational numbers could be |> > handy. That's because rational numbers are exact, irrational numbers

Re: Rational Numbers

2007-01-12 Thread Facundo Batista
Noud Aldenhoven wrote: > There are a (small) couple of other issues where rational numbers could be > handy. That's because rational numbers are exact, irrational numbers (in > python) aren't. But these issues are probably too mathematical to be used in For the sake of me

Re: Rational Numbers

2007-01-12 Thread Nick Maclaren
In article <[EMAIL PROTECTED]>, Carsten Haese <[EMAIL PROTECTED]> writes: |> |> Ah, so now you're putting words in the BDFL's mouth. ;) |> |> The pronouncement does say "The needs outlined in the rationale section |> have been addressed to some extent by the acceptance of PEP 327 for |> decimal

Re: Rational Numbers

2007-01-12 Thread Carsten Haese
> Facundo Batista <[EMAIL PROTECTED]> writes: > |> > |> Python does not have rational numbers. > |> > |> > |> > |> There's a (rejected) PEP about this, PEP-239: > |> > |> > |> > |> http://www.python.org/dev/peps/pep-0239/ > |> &g

Re: Rational Numbers

2007-01-12 Thread Nick Maclaren
: |> > |> |> > |> > When I was programming in a mathematical project I began to wonder if python |> > |> > supports rational numbers[1]. In a language like magma[2] it's not such a |> > |> > problem. Does python supports something simular? |>

Re: Rational Numbers

2007-01-12 Thread Carsten Haese
On Thu, 2007-01-11 at 23:47 +, Nick Maclaren wrote: > In article <[EMAIL PROTECTED]>, > Facundo Batista <[EMAIL PROTECTED]> writes: > |> Noud Aldenhoven wrote: > |> > |> > When I was programming in a mathematical project I began to wonder if > python

Re: Rational Numbers

2007-01-11 Thread Nick Maclaren
In article <[EMAIL PROTECTED]>, Facundo Batista <[EMAIL PROTECTED]> writes: |> Noud Aldenhoven wrote: |> |> > When I was programming in a mathematical project I began to wonder if python |> > supports rational numbers[1]. In a language like magma[2] it's n

Re: Rational Numbers

2007-01-11 Thread Robert Kern
Noud Aldenhoven wrote: > I'm a mathematician (in learning, with a bad feeling for English) and > don't trust irrational numbers in programming languages. You may want to look at SAGE. It provides a ton of good mathematical code. http://sage.scipy.org/sage/ -- Robert Kern "I have come to bel

Re: Rational Numbers

2007-01-11 Thread Noud Aldenhoven
On 1/11/07, Facundo Batista <[EMAIL PROTECTED]> wrote: Python does not have rational numbers. Ah, oke. Thank you, it seems I have enough information why they aren't included in the core. Question: Why do you say that it's a problem? Well... Perhaps I word it wrong. I

Re: Rational Numbers

2007-01-11 Thread Facundo Batista
Noud Aldenhoven wrote: > When I was programming in a mathematical project I began to wonder if python > supports rational numbers[1]. In a language like magma[2] it's not such a > problem. Does python supports something simular? Python does not have rational numbers. There'

Rational Numbers

2007-01-11 Thread Noud Aldenhoven
Hello, When I was programming in a mathematical project I began to wonder if python supports rational numbers[1]. In a language like magma[2] it's not such a problem. Does python supports something simular? Greetings, Noud Aldenhoven -- <:3 )~ [1] http://en.wikipedia.org/wiki/Rationa

Re: rational numbers

2006-01-17 Thread Carsten Haese
On Tue, 2006-01-17 at 11:22, Paul Rubin wrote: > Schüle Daniel <[EMAIL PROTECTED]> writes: > > does anybody know modules which make rational numbers available? > > Try gmpy.mpq (google for gmpy). > > > and are there considerations to add them to the core, like

Re: rational numbers

2006-01-17 Thread Paul Rubin
Schüle Daniel <[EMAIL PROTECTED]> writes: > does anybody know modules which make rational numbers available? > and are there considerations to add them to the core, like > complex numbers (maybe in Python 3) I think it's not likely. In Scheme, (/ 5 2) is the rational number 5

Re: rational numbers

2006-01-17 Thread Paul Rubin
Schüle Daniel <[EMAIL PROTECTED]> writes: > does anybody know modules which make rational numbers available? Try gmpy.mpq (google for gmpy). > and are there considerations to add them to the core, like > complex numbers (maybe in Python 3) I don't think it's been

rational numbers

2006-01-17 Thread Schüle Daniel
Hello NG, recently I was using Scheme and Ruby and was really nicely surprised to find there support for the computing with rational numbers for example this how it works in Ruby mond:/pool/PROG/ruby # irb irb(main):001:0> irb(main):002:0* require "mathn" => true irb(main):003

Re: precision problems in base conversion of rational numbers

2005-07-07 Thread [EMAIL PROTECTED]
Raymond Hettinger wrote: > > > For a simple example, convert both 10247448370872321 and > > > 10247448370872319 from base ten to 4 digits of hex. The calculations > > > need to be carried out to 15 places of hex (or 17 places of decimal) > > > just to determine whether the fourth hex digit is a

Re: precision problems in base conversion of rational numbers

2005-07-06 Thread Raymond Hettinger
> > For a simple example, convert both 10247448370872321 and > > 10247448370872319 from base ten to 4 digits of hex. The calculations > > need to be carried out to 15 places of hex (or 17 places of decimal) > > just to determine whether the fourth hex digit is a 7 or 8: > > > > >>> hex(1024744

Re: precision problems in base conversion of rational numbers

2005-07-06 Thread [EMAIL PROTECTED]
Raymond Hettinger wrote: > [Terry Hancock] > > > Needless to say, the conventional floating point numbers in Python > > > are actually stored as *binary*, which is why there is a "decimal" > > > module (which is new). > > > > > > If you're going to be converting between bases anyway, it probably

Re: precision problems in base conversion of rational numbers

2005-07-06 Thread Raymond Hettinger
[Terry Hancock] > > Needless to say, the conventional floating point numbers in Python > > are actually stored as *binary*, which is why there is a "decimal" > > module (which is new). > > > > If you're going to be converting between bases anyway, it probably > > makes little difference whether you

Re: precision problems in base conversion of rational numbers

2005-07-05 Thread Dan Bishop
es. It aims to take any of whole > numbers (python ints, longs, or Decimals), rational numbers (n / m n, > m whole) and floating points (the best I can do for reals), and > convert them to any base between 2 and 36, to desired precision. ... > I've discovered empirically that I ha

Re: precision problems in base conversion of rational numbers

2005-07-05 Thread Brian van den Broek
mbers (python ints, longs, or Decimals), rational numbers (n / m n, >>m whole) and floating points (the best I can do for reals), and >>convert them to any base between 2 and 36, to desired precision. Thanks to Terry and mensanator for the replies. To consolidate, I respond to Ter

Re: precision problems in base conversion of rational numbers

2005-07-05 Thread [EMAIL PROTECTED]
bases. It aims to take any of whole > numbers (python ints, longs, or Decimals), rational numbers (n / m n, > m whole) and floating points (the best I can do for reals), and > convert them to any base between 2 and 36, to desired precision. > > I'm pretty close but I know I am not

Re: precision problems in base conversion of rational numbers

2005-07-05 Thread Terry Hancock
On Monday 04 July 2005 06:11 am, Brian van den Broek wrote: > As a self-directed learning exercise I've been working on a script to > convert numbers to arbitrary bases. It aims to take any of whole > numbers (python ints, longs, or Decimals), rational numbers (n / m n, > m wh

precision problems in base conversion of rational numbers

2005-07-04 Thread Brian van den Broek
longs, or Decimals), rational numbers (n / m n, m whole) and floating points (the best I can do for reals), and convert them to any base between 2 and 36, to desired precision. I'm pretty close but I know I am not handling the precision quite right. Nothing other than understanding hangs