Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > comp.lang.python > #71366
| From | Mark H Harris <harrismh777@gmail.com> |
|---|---|
| Newsgroups | comp.lang.python |
| Subject | Re: Fortran (Was: The "does Python have variables?" debate) |
| Date | 2014-05-11 23:10 -0500 |
| Organization | Aioe.org NNTP Server |
| Message-ID | <lkphk8$88v$1@speranza.aioe.org> (permalink) |
| References | (11 earlier) <roy-42828C.09423710052014@news.panix.com> <lkn4mh$4d5$1@speranza.aioe.org> <87mweotfe5.fsf@dpt-info.u-strasbg.fr> <lkoh14$rpq$1@speranza.aioe.org> <mailman.9906.1399865515.18130.python-list@python.org> |
On 5/11/14 10:10 PM, Dave Angel wrote: > On 05/11/2014 02:54 PM, Mark H Harris wrote: > >> >> >julia> sin(BigFloat(π/4)) >> > 7.0710678118654750275194295621751674626154323953749278952436611913748 >> > 20215180412e-01 with 256 bits of precision >> > > That answer doesn't seem to come anywhere near 256 bits of precision. > > Using Python 3.2, > > >>> x=70710678118654750275194295621751674626154323953749278952436611913748 > >>> x*x > 4999999999999999693838300213161705693483516931249926767981110058185818806614907837502621065882204197129973479350206261627418690991407504 > > > Not that this is surprising, but it does make a terrible ad for how > great Julia is. > Dave, you get the golden egg! I expected D'Aprano to catch it first! Yes, BigFloat does the same dumb thing Python's Decimal does. π/4 is not a BigFloat, and BigFloat simply makes the 16 digit float into a 256 bit float, the sin of which will only be 16 digits accurate (more or less). It has nothing to do with the language (Python vs. Julia) it has to do with the way the BigFloat is formed. So let's fix it by forming the π constant as a BigFloat constant: >julia> n = BigFloat(1) >1e+00 with 256 bits of precision >julia> π = atan(n/5)*16 - atan(n/239)*4 >3.141592653589793238462643383279502884197169399375105820974944592307816406286198e+00 >with 256 bits of precision >julia> S = sin(π/4) >7.07106781186547524400844362104849039284835937688474036588339868995366239231051e-01 >with 256 bits of precision >julia> S * S >4.999999999999999999999999999999999999999999999999999999999999999999999999999957e-01 >with 256 bits of precision Not too bad... marcus
Back to comp.lang.python | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
Re: The “does Python have variables?” debate Ned Batchelder <ned@nedbatchelder.com> - 2014-05-06 21:19 -0400
Re: The “does Python have variables?” debate Marko Rauhamaa <marko@pacujo.net> - 2014-05-07 09:18 +0300
Re: The “does Python have variables?” debate Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-05-07 09:51 +0100
Re: The “does Python have variables?” debate Ethan Furman <ethan@stoneleaf.us> - 2014-05-07 06:00 -0700
Re: The “does Python have variables?” debate Marko Rauhamaa <marko@pacujo.net> - 2014-05-07 17:17 +0300
Re: The “does Python have variables?” debate Chris Angelico <rosuav@gmail.com> - 2014-05-08 00:30 +1000
Re: The “does Python have variables?” debate Chris Angelico <rosuav@gmail.com> - 2014-05-08 00:14 +1000
Re: The “does Python have variables?” debate Marko Rauhamaa <marko@pacujo.net> - 2014-05-07 17:20 +0300
Re: The “does Python have variables?” debate Jerry Hill <malaclypse2@gmail.com> - 2014-05-07 11:48 -0400
Re: The “does Python have variables?” debate Mark H Harris <harrismh777@gmail.com> - 2014-05-07 14:31 -0500
Re: The “does Python have variables?” debate Ben Finney <ben@benfinney.id.au> - 2014-05-08 05:57 +1000
Re: The “does Python have variables?” debate Marko Rauhamaa <marko@pacujo.net> - 2014-05-08 00:15 +0300
Re: The “does Python have variables?” debate Mark H Harris <harrismh777@gmail.com> - 2014-05-07 16:35 -0500
Re: The “does Python have variables?” debate Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-08 01:27 +0000
Re: The “does Python have variables?” debate Chris Angelico <rosuav@gmail.com> - 2014-05-08 12:09 +1000
Re: The “does Python have variables?” debate Steven D'Aprano <steve@pearwood.info> - 2014-05-08 03:41 +0000
Re: The “does Python have variables?” debate Dan Sommers <dan@tombstonezero.net> - 2014-05-08 03:43 +0000
Re: The “does Python have variables?” debate Mark H Harris <harrismh777@gmail.com> - 2014-05-09 17:34 -0500
Re: The “does Python have variables?” debate Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-10 01:11 +0000
Re: The “does Python have variables?” debate Larry Hudson <orgnut@yahoo.com> - 2014-05-10 00:46 -0700
Re: The “does Python have variables?” debate Ben Finney <ben@benfinney.id.au> - 2014-05-08 10:35 +1000
Re: The “does Python have variables?” debate Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-08 01:32 +0000
Re: The “does Python have variables?” debate Marko Rauhamaa <marko@pacujo.net> - 2014-05-08 09:19 +0300
Re: The “does Python have variables?” debate Ben Finney <ben@benfinney.id.au> - 2014-05-08 16:40 +1000
Re: The "does Python have variables?" debate Rustom Mody <rustompmody@gmail.com> - 2014-05-07 23:50 -0700
Re: The "does Python have variables?" debate Marko Rauhamaa <marko@pacujo.net> - 2014-05-08 10:03 +0300
Re: The “does Python have variables?” debate Ned Batchelder <ned@nedbatchelder.com> - 2014-05-07 21:33 -0400
Re: The “does Python have variables?” debate Johannes Schneider <johannes.schneider@galileo-press.de> - 2014-05-08 09:26 +0200
Re: The “does Python have variables?” debate Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-09 00:54 +0000
Re: The “does Python have variables?” debate Joseph Martinot-Lagarde <joseph.martinot-lagarde@m4x.org> - 2014-05-08 10:07 +0200
Re: The “does Python have variables?” debate Chris Angelico <rosuav@gmail.com> - 2014-05-08 18:14 +1000
Re: The “does Python have variables?” debate Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-08 13:22 +0000
Re: The “does Python have variables?” debate Ben Finney <ben@benfinney.id.au> - 2014-05-08 18:34 +1000
Re: The “does Python have variables?” debate Marko Rauhamaa <marko@pacujo.net> - 2014-05-08 12:43 +0300
Re: The “does Python have variables?” debate Ben Finney <ben@benfinney.id.au> - 2014-05-08 21:14 +1000
Re: The “does Python have variables?” debate Marko Rauhamaa <marko@pacujo.net> - 2014-05-08 15:01 +0300
Re: The “does Python have variables?” debate Ben Finney <ben@benfinney.id.au> - 2014-05-09 05:14 +1000
Re: The “does Python have variables?” debate Ethan Furman <ethan@stoneleaf.us> - 2014-05-08 14:50 -0700
Re: The “does Python have variables?” debate Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-09 00:02 +0000
Re: The � debate Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2014-05-09 13:10 +1200
Re: The � debate Ben Finney <ben@benfinney.id.au> - 2014-05-09 13:13 +1000
Re: The � debate Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-10 01:34 +0000
Re: The � debate Mark H Harris <harrismh777@gmail.com> - 2014-05-09 21:34 -0500
Re: The � debate Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2014-05-10 17:58 +1200
Re: The � debate Chris Angelico <rosuav@gmail.com> - 2014-05-10 17:10 +1000
Re: The � debate Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-10 07:48 +0000
Re: The � debate Chris Angelico <rosuav@gmail.com> - 2014-05-10 18:01 +1000
Re: The � debate Marko Rauhamaa <marko@pacujo.net> - 2014-05-10 11:21 +0300
Re: The � debate Rustom Mody <rustompmody@gmail.com> - 2014-05-10 02:05 -0700
Re: The � debate Ethan Furman <ethan@stoneleaf.us> - 2014-05-10 12:30 -0700
Re: The � debate Marko Rauhamaa <marko@pacujo.net> - 2014-05-10 11:18 +0300
Re: The � debate Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-10 09:31 +0000
Re: The “does Python have variables?” debate Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-08 13:18 +0000
Re: The “does Python have variables?” debate Chris Angelico <rosuav@gmail.com> - 2014-05-08 23:46 +1000
Re: The “does Python have variables?” debate Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-08 14:22 +0000
Re: The “does Python have variables?” debate Chris Angelico <rosuav@gmail.com> - 2014-05-09 00:51 +1000
Re: The “does Python have variables?” debate Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-08 16:04 +0000
Re: The “does Python have variables?” debate Chris Angelico <rosuav@gmail.com> - 2014-05-09 02:10 +1000
Re: The “does Python have variables?” debate Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2014-05-08 21:02 -0400
Re: The “does Python have variables?” debate Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-09 01:32 +0000
Re: The “does Python have variables?” debate Roy Smith <roy@panix.com> - 2014-05-08 22:21 -0400
Re: The “does Python have variables?” debate Chris Angelico <rosuav@gmail.com> - 2014-05-09 12:31 +1000
Re: The "does Python have variables?" debate Rustom Mody <rustompmody@gmail.com> - 2014-05-08 22:40 -0700
Re: The "does Python have variables?" debate Chris Angelico <rosuav@gmail.com> - 2014-05-09 15:51 +1000
Re: The "does Python have variables?" debate Rustom Mody <rustompmody@gmail.com> - 2014-05-09 07:09 -0700
Re: The "does Python have variables?" debate Chris Angelico <rosuav@gmail.com> - 2014-05-10 00:29 +1000
Re: The "does Python have variables?" debate Rustom Mody <rustompmody@gmail.com> - 2014-05-09 09:07 -0700
Re: The “does Python have variables?â€瑩 debate Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2014-05-09 19:51 -0400
Re: The “does Python have variables?â€瑩 debate Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-05-10 01:03 +0100
Fortran (Was: The "does Python have variables?" debate) Roy Smith <roy@panix.com> - 2014-05-10 09:42 -0400
Re: Fortran (Was: The "does Python have variables?" debate) Terry Reedy <tjreedy@udel.edu> - 2014-05-10 14:31 -0400
Re: Fortran (Was: The "does Python have variables?" debate) Mark H Harris <harrismh777@gmail.com> - 2014-05-11 01:17 -0500
Re: Fortran (Was: The "does Python have variables?" debate) Rustom Mody <rustompmody@gmail.com> - 2014-05-11 00:01 -0700
Re: Fortran (Was: The "does Python have variables?" debate) Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-11 07:09 +0000
Re: Fortran (Was: The "does Python have variables?" debate) Tomasz Rola <rtomek@ceti.pl> - 2014-05-11 18:09 +0200
Re: Fortran Marko Rauhamaa <marko@pacujo.net> - 2014-05-11 19:27 +0300
Re: Fortran Roy Smith <roy@panix.com> - 2014-05-11 13:51 -0400
Re: Fortran Chris Angelico <rosuav@gmail.com> - 2014-05-12 04:08 +1000
Re: Fortran Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-11 23:51 +0000
Re: Fortran Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-05-12 01:27 +0100
Re: Fortran Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-12 02:28 +0000
Re: Fortran Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-05-12 10:05 +0100
Re: Fortran Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2014-05-12 20:52 -0400
Re: Fortran Ethan Furman <ethan@stoneleaf.us> - 2014-05-11 11:05 -0700
Re: Fortran Chris Angelico <rosuav@gmail.com> - 2014-05-12 04:33 +1000
Re: Fortran Roy Smith <roy@panix.com> - 2014-05-11 14:43 -0400
Re: Fortran Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-11 23:15 +0000
Re: Fortran MRAB <python@mrabarnett.plus.com> - 2014-05-12 00:51 +0100
Re: Fortran Roy Smith <roy@panix.com> - 2014-05-11 20:14 -0400
Re: Fortran alister <alister.nospam.ware@ntlworld.com> - 2014-05-12 14:14 +0000
Re: Fortran Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-12 01:11 +0000
Re: Fortran Dave Angel <d@davea.name> - 2014-05-11 23:27 -0400
Re: Fortran Grant Edwards <invalid@invalid.invalid> - 2014-05-12 14:07 +0000
Re: Fortran Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2014-05-11 21:12 -0400
Re: Fortran (Was: The "does Python have variables?" debate) Chris Angelico <rosuav@gmail.com> - 2014-05-12 02:42 +1000
Re: Fortran Tomasz Rola <rtomek@ceti.pl> - 2014-05-11 20:04 +0200
Re: Fortran Chris Angelico <rosuav@gmail.com> - 2014-05-12 04:12 +1000
Re: Fortran (Was: The "does Python have variables?" debate) Alain Ketterlin <alain@dpt-info.u-strasbg.fr> - 2014-05-11 19:05 +0200
Re: Fortran (Was: The "does Python have variables?" debate) Mark H Harris <harrismh777@gmail.com> - 2014-05-11 13:54 -0500
Re: Fortran (Was: The "does Python have variables?" debate) Chris Angelico <rosuav@gmail.com> - 2014-05-12 04:59 +1000
Re: Fortran (Was: The "does Python have variables?" debate) Mark H Harris <harrismh777@gmail.com> - 2014-05-11 14:14 -0500
Re: Fortran (Was: The "does Python have variables?" debate) albert@spenarnc.xs4all.nl (Albert van der Horst) - 2014-05-29 14:06 +0000
Re: Fortran (Was: The "does Python have variables?" debate) Peter Pearson <ppearson@nowhere.invalid> - 2014-05-29 17:53 +0000
Re: Fortran (Was: The "does Python have variables?" debate) Dave Angel <davea@davea.name> - 2014-05-11 23:10 -0400
Re: Fortran (Was: The "does Python have variables?" debate) Mark H Harris <harrismh777@gmail.com> - 2014-05-11 23:10 -0500
Re: Fortran (Was: The "does Python have variables?" debate) Mark H Harris <harrismh777@gmail.com> - 2014-05-11 23:26 -0500
Re: Fortran (Was: The "does Python have variables?" debate) Chris Angelico <rosuav@gmail.com> - 2014-05-12 14:53 +1000
Re: Fortran (Was: The "does Python have variables?" debate) Alain Ketterlin <alain@dpt-info.u-strasbg.fr> - 2014-05-12 10:44 +0200
Re: Fortran (Was: The "does Python have variables?" debate) Mark H Harris <harrismh777@gmail.com> - 2014-05-13 00:33 -0500
Re: Fortran (Was: The "does Python have variables?" debate) Steven D'Aprano <steve@pearwood.info> - 2014-05-13 05:48 +0000
Re: Fortran (Was: The "does Python have variables?" debate) Mark H Harris <harrismh777@gmail.com> - 2014-05-13 00:55 -0500
Re: Fortran (Was: The "does Python have variables?" debate) Chris Angelico <rosuav@gmail.com> - 2014-05-13 15:56 +1000
Re: Fortran (Was: The "does Python have variables?" debate) Steven D'Aprano <steve@pearwood.info> - 2014-05-13 09:34 +0000
Re: Fortran (Was: The "does Python have variables?" debate) Chris Angelico <rosuav@gmail.com> - 2014-05-13 20:00 +1000
Re: Fortran (Was: The "does Python have variables?" debate) Rustom Mody <rustompmody@gmail.com> - 2014-05-13 03:44 -0700
Re: Fortran (Was: The "does Python have variables?" debate) Chris Angelico <rosuav@gmail.com> - 2014-05-13 20:50 +1000
Re: Fortran (Was: The "does Python have variables?" debate) Gene Heskett <gheskett@wdtv.com> - 2014-05-13 02:31 -0400
Re: Fortran (Was: The "does Python have variables?" debate) Steven D'Aprano <steve@pearwood.info> - 2014-05-13 07:22 +0000
Re: Fortran (Was: The "does Python have variables?" debate) Roy Smith <roy@panix.com> - 2014-05-13 07:16 -0400
Re: Fortran (Was: The "does Python have variables?" debate) Chris Angelico <rosuav@gmail.com> - 2014-05-13 21:21 +1000
Re: Fortran (Was: The "does Python have variables?" debate) Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-05-13 14:42 +0100
Re: Fortran (Was: The "does Python have variables?" debate) Gene Heskett <gheskett@wdtv.com> - 2014-05-13 07:42 -0400
Re: Fortran Alain Ketterlin <alain@dpt-info.u-strasbg.fr> - 2014-05-13 19:33 +0200
Re: Fortran Marko Rauhamaa <marko@pacujo.net> - 2014-05-13 22:57 +0300
Re: Fortran Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-14 00:10 +0000
Re: Fortran Ian Kelly <ian.g.kelly@gmail.com> - 2014-05-13 21:43 -0600
Re: Fortran Marko Rauhamaa <marko@pacujo.net> - 2014-05-14 07:35 +0300
Re: Fortran Steven D'Aprano <steve@pearwood.info> - 2014-05-14 06:58 +0000
Re: Fortran Marko Rauhamaa <marko@pacujo.net> - 2014-05-14 11:46 +0300
Re: Fortran Sturla Molden <sturla.molden@gmail.com> - 2014-05-14 23:05 +0000
struct.unpack: why 's' fmt char convert to bytestring GuoChao <cx63@outlook.com> - 2014-05-15 20:34 +0800
Re: struct.unpack: why 's' fmt char convert to bytestring Dave Angel <davea@davea.name> - 2014-05-15 09:49 -0400
Re: struct.unpack: why 's' fmt char convert to bytestring MRAB <python@mrabarnett.plus.com> - 2014-05-15 15:47 +0100
Re: Fortran Alain Ketterlin <alain@dpt-info.u-strasbg.fr> - 2014-05-14 15:13 +0200
Re: Fortran albert@spenarnc.xs4all.nl (Albert van der Horst) - 2014-05-29 14:26 +0000
Re: Fortran Marko Rauhamaa <marko@pacujo.net> - 2014-05-29 17:50 +0300
Re: Fortran Chris Angelico <rosuav@gmail.com> - 2014-05-30 00:58 +1000
Re: Fortran Marko Rauhamaa <marko@pacujo.net> - 2014-05-29 18:09 +0300
Re: Fortran Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-29 17:57 +0000
Re: Fortran Marko Rauhamaa <marko@pacujo.net> - 2014-05-29 21:55 +0300
Re: The “does Python have variables?” debate Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-05-09 09:13 +0100
Re: The “does Python have variables?” debate Michael Torrie <torriem@gmail.com> - 2014-05-08 08:06 -0600
Re: The “does Python have variables?” debate Chris Angelico <rosuav@gmail.com> - 2014-05-09 00:13 +1000
Re: The “does Python have variables?” debate Terry Reedy <tjreedy@udel.edu> - 2014-05-08 15:21 -0400
Re: The “does Python have variables?” debate Marko Rauhamaa <marko@pacujo.net> - 2014-05-08 23:06 +0300
Re: The “does Python have variables?” debate Ethan Furman <ethan@stoneleaf.us> - 2014-05-08 15:36 -0700
Re: The “does Python have variables?” debate Ethan Furman <ethan@stoneleaf.us> - 2014-05-08 17:05 -0700
Re: The “does Python have variables?” debate Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-05-09 01:47 +0100
Re: The “does Python have variables?” debate Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-08 00:57 +0000
Re: The “does Python have variables?” debate Roy Smith <roy@panix.com> - 2014-05-08 08:41 -0400
Re: The “does Python have variables?” debate Chris Angelico <rosuav@gmail.com> - 2014-05-08 22:54 +1000
Re: The “does Python have variables?” debate Ethan Furman <ethan@stoneleaf.us> - 2014-05-08 06:18 -0700
Re: The “does Python have variables?” debate Marko Rauhamaa <marko@pacujo.net> - 2014-05-08 17:03 +0300
Re: The “does Python have variables?” debate Ethan Furman <ethan@stoneleaf.us> - 2014-05-08 16:09 -0700
Re: The “does Python have variables?” debate "Neil D. Cerutti" <neilc@norwich.edu> - 2014-05-08 10:47 -0400
csiph-web