Re: Best search algorithm to find condition within a range

From	Marko Rauhamaa <marko@pacujo.net>
Newsgroups	comp.lang.python
Subject	Re: Best search algorithm to find condition within a range
Date	2015-04-09 20:43 +0300
Organization	A noiseless patient Spider
Message-ID	<87sic9b3jk.fsf@elektro.pacujo.net> (permalink)
References	(10 earlier) <874mopzarw.fsf@elektro.pacujo.net> <552696be$0$13012$c3e8da3$5496439d@news.astraweb.com> <mailman.169.1428593659.12925.python-list@python.org> <87y4m1b76f.fsf@elektro.pacujo.net> <mailman.176.1428597801.12925.python-list@python.org>

Show all headers | View raw

Chris Angelico <rosuav@gmail.com>:

> For low-level bit manipulation work, you usually want an *unsigned*
> integer of specific size, with well defined wrap-around behaviour.
> When do you actually want a signed integer with well-defined overflow
> behaviour?

Bit manipulation is not the issue here.

The reason for signed, wrapping integers is that you want to be able to
perform signed subtractions. Consider for example time differences that
are often expressed as signed second and/or nanosecond counts that are
at the brink of overflowing. You want to be able to perform usual
arithmetic operations even if the intermediate results overflow.

A classic analogy: the roots of a cubic equation can be figured out
explicitly with Cardano's method <URL:
http://www.math.vanderbilt.edu/~schectex/courses/cubic/>. The
algebraists were impressed with the solution, but to their
consternation, the formula involved taking the square root of a negative
number even when all three solutions were real.

Temporary integer overflows and excursions into the complex number space
should not be shunned unnecessarily.


Marko

Thread

Best search algorithm to find condition within a range jonas.thornvall@gmail.com - 2015-04-07 02:44 -0700
  Re: Best search algorithm to find condition within a range Dave Angel <davea@davea.name> - 2015-04-07 09:29 -0400
    Re: Best search algorithm to find condition within a range jonas.thornvall@gmail.com - 2015-04-07 07:10 -0700
      Re: Best search algorithm to find condition within a range Dave Angel <davea@davea.name> - 2015-04-07 10:26 -0400
      Re: Best search algorithm to find condition within a range Chris Angelico <rosuav@gmail.com> - 2015-04-08 00:34 +1000
    Re: Best search algorithm to find condition within a range Denis McMahon <denismfmcmahon@gmail.com> - 2015-04-07 14:29 +0000
      Re: Best search algorithm to find condition within a range jonas.thornvall@gmail.com - 2015-04-07 07:36 -0700
        Re: Best search algorithm to find condition within a range Chris Angelico <rosuav@gmail.com> - 2015-04-08 00:49 +1000
          Re: Best search algorithm to find condition within a range Grant Edwards <invalid@invalid.invalid> - 2015-04-07 15:05 +0000
            Re: Best search algorithm to find condition within a range Dave Angel <davea@davea.name> - 2015-04-07 11:23 -0400
            Re: Best search algorithm to find condition within a range Chris Angelico <rosuav@gmail.com> - 2015-04-08 01:37 +1000
            Re: Best search algorithm to find condition within a range MRAB <python@mrabarnett.plus.com> - 2015-04-07 17:02 +0100
        Re: Best search algorithm to find condition within a range MRAB <python@mrabarnett.plus.com> - 2015-04-07 16:00 +0100
          Re: Best search algorithm to find condition within a range jonas.thornvall@gmail.com - 2015-04-07 08:43 -0700
            Re: Best search algorithm to find condition within a range Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-04-08 08:51 +1000
              Re: Best search algorithm to find condition within a range Chris Angelico <rosuav@gmail.com> - 2015-04-08 11:46 +1000
        Re: Best search algorithm to find condition within a range Dave Angel <davea@davea.name> - 2015-04-07 11:04 -0400
        Re: Best search algorithm to find condition within a range Ian Kelly <ian.g.kelly@gmail.com> - 2015-04-07 09:06 -0600
          Re: Best search algorithm to find condition within a range jonas.thornvall@gmail.com - 2015-04-07 08:47 -0700
            Re: Best search algorithm to find condition within a range Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2015-04-07 20:06 -0400
            Re: Best search algorithm to find condition within a range Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2015-04-08 12:49 +1200
        Re: Best search algorithm to find condition within a range Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-04-08 08:36 +1000
          Re: Best search algorithm to find condition within a range Cameron Simpson <cs@zip.com.au> - 2015-04-08 08:51 +1000
        Re: Best search algorithm to find condition within a range Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2015-04-07 20:01 -0400
        Re: Best search algorithm to find condition within a range albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-04-18 18:08 +0000
          Re: Best search algorithm to find condition within a range Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-04-19 23:02 +1000
            Re: Best search algorithm to find condition within a range Marko Rauhamaa <marko@pacujo.net> - 2015-04-19 17:56 +0300
              Re: Best search algorithm to find condition within a range Gene Heskett <gheskett@wdtv.com> - 2015-04-19 11:17 -0400
              Re: Best search algorithm to find condition within a range Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-04-20 12:53 +1000
            Re: Best search algorithm to find condition within a range Dave Angel <davea@davea.name> - 2015-04-19 14:52 -0400
            Re: Best search algorithm to find condition within a range Paul Rubin <no.email@nospam.invalid> - 2015-04-19 13:44 -0700
            Re: Best search algorithm to find condition within a range albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-04-25 14:49 +0000
      Re: Best search algorithm to find condition within a range jonas.thornvall@gmail.com - 2015-04-07 09:18 -0700
  Re: Best search algorithm to find condition within a range Ian Kelly <ian.g.kelly@gmail.com> - 2015-04-07 08:32 -0600
    Re: Best search algorithm to find condition within a range jonas.thornvall@gmail.com - 2015-04-07 08:40 -0700
      Re: Best search algorithm to find condition within a range Dave Angel <davea@davea.name> - 2015-04-07 12:33 -0400
        Re: Best search algorithm to find condition within a range jonas.thornvall@gmail.com - 2015-04-07 10:07 -0700
          Re: Best search algorithm to find condition within a range Ian Kelly <ian.g.kelly@gmail.com> - 2015-04-07 11:44 -0600
            Re: Best search algorithm to find condition within a range Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-04-08 10:38 +1000
              Re: Best search algorithm to find condition within a range Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-04-08 11:18 +1000
                Re: Best search algorithm to find condition within a range Ian Kelly <ian.g.kelly@gmail.com> - 2015-04-08 08:37 -0600
              Re: Best search algorithm to find condition within a range jonas.thornvall@gmail.com - 2015-04-07 23:19 -0700
                Re: Best search algorithm to find condition within a range Mel Wilson <mwilson@the-wire.com> - 2015-04-08 13:39 +0000
                Re: Best search algorithm to find condition within a range jonas.thornvall@gmail.com - 2015-04-08 07:56 -0700
                Re: Best search algorithm to find condition within a range Mel Wilson <mwilson@the-wire.com> - 2015-04-08 17:33 +0000
                Re: Best search algorithm to find condition within a range jonas.thornvall@gmail.com - 2015-04-08 12:28 -0700
                Re: Best search algorithm to find condition within a range jonas.thornvall@gmail.com - 2015-04-08 12:36 -0700
                Re: Best search algorithm to find condition within a range Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-04-08 21:28 +0100
                Re: Best search algorithm to find condition within a range Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-04-08 21:29 +0100
          Re: Best search algorithm to find condition within a range Terry Reedy <tjreedy@udel.edu> - 2015-04-07 14:55 -0400
          Re: Best search algorithm to find condition within a range Ian Kelly <ian.g.kelly@gmail.com> - 2015-04-07 13:19 -0600
            Re: Best search algorithm to find condition within a range Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-04-07 20:27 +0100
              Re: Best search algorithm to find condition within a range jonas.thornvall@gmail.com - 2015-04-07 15:35 -0700
                Re: Best search algorithm to find condition within a range Dave Angel <davea@davea.name> - 2015-04-07 20:38 -0400
                Re: Best search algorithm to find condition within a range Ian Kelly <ian.g.kelly@gmail.com> - 2015-04-07 17:35 -0600
                Re: Best search algorithm to find condition within a range jonas.thornvall@gmail.com - 2015-04-08 00:28 -0700
                Re: Best search algorithm to find condition within a range Ian Kelly <ian.g.kelly@gmail.com> - 2015-04-08 08:35 -0600
                Re: Best search algorithm to find condition within a range jonas.thornvall@gmail.com - 2015-04-08 00:35 -0700
          Re: Best search algorithm to find condition within a range Chris Angelico <rosuav@gmail.com> - 2015-04-08 05:25 +1000
          Re: Best search algorithm to find condition within a range Ian Kelly <ian.g.kelly@gmail.com> - 2015-04-07 13:28 -0600
          Re: Best search algorithm to find condition within a range Serhiy Storchaka <storchaka@gmail.com> - 2015-04-07 23:57 +0300
          Re: Best search algorithm to find condition within a range Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-04-08 10:18 +1000
            Re: Best search algorithm to find condition within a range Marko Rauhamaa <marko@pacujo.net> - 2015-04-08 07:31 +0300
      Re: Best search algorithm to find condition within a range Ian Kelly <ian.g.kelly@gmail.com> - 2015-04-07 14:15 -0600
      Re: Best search algorithm to find condition within a range Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-04-07 21:42 +0100
    Re: Best search algorithm to find condition within a range Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-04-08 08:55 +1000
      Re: Best search algorithm to find condition within a range Ian Kelly <ian.g.kelly@gmail.com> - 2015-04-07 17:30 -0600
  Re: Best search algorithm to find condition within a range Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-04-08 08:57 +1000
    Re: Best search algorithm to find condition within a range Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2015-04-08 12:59 +1200
      Re: Best search algorithm to find condition within a range Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-04-08 02:39 +0100
      Re: Best search algorithm to find condition within a range jonas.thornvall@gmail.com - 2015-04-07 23:12 -0700
    Re: Best search algorithm to find condition within a range Chris Angelico <rosuav@gmail.com> - 2015-04-08 11:49 +1000
      Re: Best search algorithm to find condition within a range Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-04-09 12:32 +1000
        Re: Best search algorithm to find condition within a range Chris Angelico <rosuav@gmail.com> - 2015-04-09 12:39 +1000
          Re: Best search algorithm to find condition within a range wxjmfauth@gmail.com - 2015-04-08 23:14 -0700
    Re: Best search algorithm to find condition within a range jonas.thornvall@gmail.com - 2015-04-07 22:50 -0700
    Re: Best search algorithm to find condition within a range wxjmfauth@gmail.com - 2015-04-07 23:07 -0700
      Re: Best search algorithm to find condition within a range wxjmfauth@gmail.com - 2015-04-07 23:18 -0700
        Re: Best search algorithm to find condition within a range Denis McMahon <denismfmcmahon@gmail.com> - 2015-04-08 17:27 +0000
          Re: Best search algorithm to find condition within a range wxjmfauth@gmail.com - 2015-04-08 10:50 -0700
    Re: Best search algorithm to find condition within a range BartC <bc@freeuk.com> - 2015-04-08 22:22 +0100
      Re: Best search algorithm to find condition within a range Marko Rauhamaa <marko@pacujo.net> - 2015-04-09 01:06 +0300
        Re: Best search algorithm to find condition within a range Chris Kaynor <ckaynor@zindagigames.com> - 2015-04-08 17:01 -0700
        Re: Best search algorithm to find condition within a range BartC <bc@freeuk.com> - 2015-04-09 10:19 +0100
          Re: Best search algorithm to find condition within a range Marko Rauhamaa <marko@pacujo.net> - 2015-04-09 13:00 +0300
            Re: Best search algorithm to find condition within a range Alain Ketterlin <alain@dpt-info.u-strasbg.fr> - 2015-04-09 13:57 +0200
              Re: Best search algorithm to find condition within a range Marko Rauhamaa <marko@pacujo.net> - 2015-04-09 15:45 +0300
                Re: Best search algorithm to find condition within a range Alain Ketterlin <alain@dpt-info.u-strasbg.fr> - 2015-04-09 14:56 +0200
                Re: Best search algorithm to find condition within a range Dave Angel <davea@davea.name> - 2015-04-09 09:19 -0400
                Re: Best search algorithm to find condition within a range Marko Rauhamaa <marko@pacujo.net> - 2015-04-09 16:33 +0300
                Re: Best search algorithm to find condition within a range Marko Rauhamaa <marko@pacujo.net> - 2015-04-09 16:49 +0300
                Re: Best search algorithm to find condition within a range Alain Ketterlin <alain@dpt-info.u-strasbg.fr> - 2015-04-09 15:57 +0200
                Re: Best search algorithm to find condition within a range Chris Angelico <rosuav@gmail.com> - 2015-04-10 00:08 +1000
                Re: Best search algorithm to find condition within a range Alain Ketterlin <alain@dpt-info.u-strasbg.fr> - 2015-04-09 16:53 +0200
                Re: Best search algorithm to find condition within a range Chris Angelico <rosuav@gmail.com> - 2015-04-10 01:02 +1000
                Re: Best search algorithm to find condition within a range jonas.thornvall@gmail.com - 2015-04-09 08:12 -0700
                Re: Best search algorithm to find condition within a range Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-04-10 01:21 +1000
                Re: Best search algorithm to find condition within a range Chris Angelico <rosuav@gmail.com> - 2015-04-10 01:36 +1000
                Re: Best search algorithm to find condition within a range MRAB <python@mrabarnett.plus.com> - 2015-04-09 17:40 +0100
                Re: Best search algorithm to find condition within a range jonas.thornvall@gmail.com - 2015-04-09 07:54 -0700
                Re: Best search algorithm to find condition within a range Ian Kelly <ian.g.kelly@gmail.com> - 2015-04-09 09:03 -0600
                Re: Best search algorithm to find condition within a range jonas.thornvall@gmail.com - 2015-04-09 08:21 -0700
                Re: Best search algorithm to find condition within a range Ian Kelly <ian.g.kelly@gmail.com> - 2015-04-09 10:23 -0600
                Re: Best search algorithm to find condition within a range Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-04-10 01:11 +1000
                Re: Best search algorithm to find condition within a range Chris Angelico <rosuav@gmail.com> - 2015-04-10 01:34 +1000
                Re: Best search algorithm to find condition within a range Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-04-10 02:15 +1000
                Re: Best search algorithm to find condition within a range Chris Angelico <rosuav@gmail.com> - 2015-04-10 02:36 +1000
                Re: Best search algorithm to find condition within a range Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-04-10 03:49 +1000
                Re: Best search algorithm to find condition within a range Marko Rauhamaa <marko@pacujo.net> - 2015-04-09 19:25 +0300
                Re: Best search algorithm to find condition within a range Chris Angelico <rosuav@gmail.com> - 2015-04-10 02:43 +1000
                Re: Best search algorithm to find condition within a range Grant Edwards <invalid@invalid.invalid> - 2015-04-09 16:53 +0000
                Re: Best search algorithm to find condition within a range Chris Angelico <rosuav@gmail.com> - 2015-04-10 03:00 +1000
                Re: Best search algorithm to find condition within a range Grant Edwards <invalid@invalid.invalid> - 2015-04-09 17:44 +0000
                Re: Best search algorithm to find condition within a range Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-04-10 03:41 +1000
                Re: Best search algorithm to find condition within a range Chris Angelico <rosuav@gmail.com> - 2015-04-10 04:07 +1000
                Re: Best search algorithm to find condition within a range Marko Rauhamaa <marko@pacujo.net> - 2015-04-09 21:14 +0300
                Re: Best search algorithm to find condition within a range Marko Rauhamaa <marko@pacujo.net> - 2015-04-09 21:11 +0300
                Re: Best search algorithm to find condition within a range Marko Rauhamaa <marko@pacujo.net> - 2015-04-09 20:43 +0300
                Re: Best search algorithm to find condition within a range Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-04-10 03:35 +1000
                Re: Best search algorithm to find condition within a range Chris Angelico <rosuav@gmail.com> - 2015-04-10 03:56 +1000
                Re: Best search algorithm to find condition within a range Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-04-10 23:18 +1000
                Re: Best search algorithm to find condition within a range Chris Angelico <rosuav@gmail.com> - 2015-04-10 23:41 +1000
                Re: Best search algorithm to find condition within a range Marko Rauhamaa <marko@pacujo.net> - 2015-04-09 21:15 +0300
                Re: Best search algorithm to find condition within a range Rustom Mody <rustompmody@gmail.com> - 2015-04-10 09:39 -0700
                Re: Best search algorithm to find condition within a range Marko Rauhamaa <marko@pacujo.net> - 2015-04-09 16:28 +0300

csiph-web