Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > comp.lang.python > #63168
| References | (12 earlier) <la7btn$u5$1@ger.gmane.org> <mailman.4882.1388808283.18130.python-list@python.org> <roy-1820F1.08551004012014@news.panix.com> <52c8c301$0$29998$c3e8da3$5496439d@news.astraweb.com> <roy-BB1659.22204004012014@news.panix.com> |
|---|---|
| From | Rustom Mody <rustompmody@gmail.com> |
| Date | 2014-01-05 10:12 +0530 |
| Subject | Re: Blog "about python 3" |
| Newsgroups | comp.lang.python |
| Message-ID | <mailman.4929.1388896998.18130.python-list@python.org> (permalink) |
On Sun, Jan 5, 2014 at 8:50 AM, Roy Smith <roy@panix.com> wrote: > I wrote: >> > I realize I'm taking this statement out of context, but yes, sometimes >> > fast is more important than correct. > > In article <52c8c301$0$29998$c3e8da3$5496439d@news.astraweb.com>, > Steven D'Aprano <steve+comp.lang.python@pearwood.info> wrote: >> Fast is never more important than correct. > > Sure it is. > > Let's imagine you're building a system which sorts packages for > delivery. You sort 1 million packages every night and put them on > trucks going out for final delivery. > > Some assumptions: > > Every second I can cut from the sort time saves me $0.01. > > If I mis-sort a package, it goes out on the wrong truck, doesn't get > discovered until the end of the day, and ends up costing me $5 > (including not just the direct cost of redelivering it, but also > factoring in ill will and having to make the occasional refund for not > meeting the promised delivery time). > > I've got a new sorting algorithm which is guaranteed to cut 10 seconds > off the sorting time (i.e. $0.10 per package). The problem is, it makes > a mistake 1% of the time. > > Let's see: > > 1 million packages x $0.10 = $100,000 saved per day because I sort them > faster. 10,000 of them will go to the wrong place, and that will cost > me $50,000 per day. By going fast and making mistakes once in a while, > I increase my profit by $50,000 per day. > > The numbers above are fabricated, but I'm sure UPS, FexEx, and all the > other package delivery companies are doing these sorts of analyses every > day. I watch the UPS guy come to my house. He gets out of his truck, > walks to my front door, rings the bell, waits approximately 5 > microseconds, leaves the package on the porch, and goes back to his > truck. I'm sure UPS has figured out that the amortized cost of the > occasional stolen or lost package is less than the cost for the delivery > guy to wait for me to come to the front door and sign for the delivery. > > Looking at another problem domain, let's say you're a contestant on > Jeopardy. If you listen to the entire clue and spend 3 seconds making > sure you know the correct answer before hitting the buzzer, it doesn't > matter if you're right or wrong. Somebody else beat you to the buzzer, > 2.5 seconds ago. > > Or, let's take an example from sports. I'm standing at home plate > holding a bat. 60 feet away from me, the pitcher is about to throw a > baseball towards me at darn close to 100 MPH (insert words like "bowl" > and "wicket" as geographically appropriate). 400 ms later, the ball is > going to be in the catcher's glove if you don't hit it. If you have an > absolutely perfect algorithm to determining if it's a ball or a strike, > which takes 500 ms to run, you're going back to the minor leagues. If > you have a 300 ms algorithm which is right 75% of the time, you're > heading to the hall of fame. Neat examples -- thanks Only minor quibble isnt $5 cost of mis-sorting a gross underestimate? I am reminded of a passage of Dijkstra in Discipline of Programming -- something to this effect He laments the fact that hardware engineers were not including overflow checks in machine ALUs. He explained as follows: If a test is moderately balanced (statistically speaking) a programmer will not mind writing an if statement If however the test is very skew -- say if 99% times, else 1% -- he will tend to skimp on the test, producing 'buggy' code [EWD would never use the bad b word or course] The cost equation for hardware is very different -- once the investment in the silicon is done with -- fixed cost albeit high -- there is no variable cost to executing that circuitry once or a zillion times Moral of Story: Intel should take up FSR [Ducks and runs for cover]
Back to comp.lang.python | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
Blog "about python 3" Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-12-30 19:41 +0000
Re: Blog "about python 3" Steven D'Aprano <steve@pearwood.info> - 2013-12-30 20:49 +0000
Re: Blog "about python 3" Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-12-30 21:29 +0000
Re: Blog "about python 3" Ethan Furman <ethan@stoneleaf.us> - 2013-12-30 14:38 -0800
Re: Blog "about python 3" Chris Angelico <rosuav@gmail.com> - 2013-12-31 12:09 +1100
Re: Blog "about python 3" Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-12-31 04:38 +0000
Re: Blog "about python 3" Chris Angelico <rosuav@gmail.com> - 2013-12-31 15:44 +1100
Re: Blog "about python 3" Ethan Furman <ethan@stoneleaf.us> - 2013-12-30 20:33 -0800
Re: Blog "about python 3" Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-12-31 04:59 +0000
Re: Blog "about python 3" Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-12-31 08:22 +0000
Re: Blog "about python 3" Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-12-31 20:53 +1100
Re: Blog "about python 3" Antoine Pitrou <solipsis@pitrou.net> - 2013-12-31 14:13 +0000
Re: Blog "about python 3" Roy Smith <roy@panix.com> - 2013-12-31 10:41 -0500
Re: Blog "about python 3" Chris Angelico <rosuav@gmail.com> - 2014-01-01 02:54 +1100
Re: Blog "about python 3" Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-12-31 15:55 +0000
Re: Blog "about python 3" Robin Becker <robin@reportlab.com> - 2014-01-02 17:36 +0000
Re: Blog "about python 3" Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-01-03 15:49 +1100
Re: Blog "about python 3" Terry Reedy <tjreedy@udel.edu> - 2014-01-03 04:01 -0500
Re: Blog "about python 3" wxjmfauth@gmail.com - 2014-01-03 02:10 -0800
Re: Blog "about python 3" Chris Angelico <rosuav@gmail.com> - 2014-01-03 21:24 +1100
Re: Blog "about python 3" Ethan Furman <ethan@stoneleaf.us> - 2014-01-03 08:56 -0800
Re: Blog "about python 3" Robin Becker <robin@reportlab.com> - 2014-01-03 12:28 +0000
Re: Blog "about python 3" Roy Smith <roy@panix.com> - 2014-01-03 09:57 -0500
Re: Blog "about python 3" Chris Angelico <rosuav@gmail.com> - 2014-01-04 02:32 +1100
Re: Blog "about python 3" Terry Reedy <tjreedy@udel.edu> - 2014-01-03 17:00 -0500
Re: Blog "about python 3" Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-01-04 04:04 +0000
Re: Blog "about python 3" Roy Smith <roy@panix.com> - 2014-01-04 08:55 -0500
Re: Blog "about python 3" Chris Angelico <rosuav@gmail.com> - 2014-01-05 01:17 +1100
Re: Blog "about python 3" wxjmfauth@gmail.com - 2014-01-04 11:10 -0800
Re: Blog "about python 3" Terry Reedy <tjreedy@udel.edu> - 2014-01-04 17:46 -0500
Re: Blog "about python 3" wxjmfauth@gmail.com - 2014-01-05 06:23 -0800
Re: Blog "about python 3" Ned Batchelder <ned@nedbatchelder.com> - 2014-01-05 10:20 -0500
Re: Blog "about python 3" Terry Reedy <tjreedy@udel.edu> - 2014-01-05 17:14 -0500
Re: Blog "about python 3" wxjmfauth@gmail.com - 2014-01-07 05:34 -0800
Re: Blog "about python 3" Terry Reedy <tjreedy@udel.edu> - 2014-01-07 09:54 -0500
Re: Blog "about python 3" Tim Delaney <timothy.c.delaney@gmail.com> - 2014-01-08 09:38 +1100
Re: Blog "about python 3" Terry Reedy <tjreedy@udel.edu> - 2014-01-07 19:02 -0500
Re: Blog "about python 3" wxjmfauth@gmail.com - 2014-01-08 01:59 -0800
Re: Blog "about python 3" Terry Reedy <tjreedy@udel.edu> - 2014-01-08 14:26 -0500
Re: Blog "about python 3" Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-01-08 20:04 +0000
Re: Blog "about python 3" Terry Reedy <tjreedy@udel.edu> - 2014-01-05 17:48 -0500
Re: Blog "about python 3" Chris Angelico <rosuav@gmail.com> - 2014-01-05 10:28 +1100
Re: Blog "about python 3" Ned Batchelder <ned@nedbatchelder.com> - 2014-01-04 12:51 -0500
Re: Blog "about python 3" Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-01-05 13:27 +1100
Re: Blog "about python 3" Chris Angelico <rosuav@gmail.com> - 2014-01-05 13:32 +1100
Re: Blog "about python 3" MRAB <python@mrabarnett.plus.com> - 2014-01-05 02:41 +0000
Re: Blog "about python 3" Roy Smith <roy@panix.com> - 2014-01-04 22:20 -0500
Re: Blog "about python 3" Rustom Mody <rustompmody@gmail.com> - 2014-01-05 10:12 +0530
Re: Blog "about python 3" Roy Smith <roy@panix.com> - 2014-01-05 00:11 -0500
Re: Blog "about python 3" Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-01-05 17:28 +1100
Re: Blog "about python 3" Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2014-01-05 14:05 -0500
Re: Blog "about python 3" Chris Angelico <rosuav@gmail.com> - 2014-01-05 15:01 +1100
Re: Blog "about python 3" Roy Smith <roy@panix.com> - 2014-01-05 11:34 -0500
Re: Blog "about python 3" Chris Angelico <rosuav@gmail.com> - 2014-01-06 03:51 +1100
Re: Blog "about python 3" Roy Smith <roy@panix.com> - 2014-01-05 12:09 -0500
Re: Blog "about python 3" Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-01-06 11:42 +1100
Re: Blog "about python 3" Terry Reedy <tjreedy@udel.edu> - 2014-01-05 17:56 -0500
Re: Blog "about python 3" Chris Angelico <rosuav@gmail.com> - 2014-01-06 10:59 +1100
Re: Blog "about python 3" Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-01-06 12:23 +1100
Re: Blog "about python 3" Chris Angelico <rosuav@gmail.com> - 2014-01-06 12:54 +1100
Re: Blog "about python 3" Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-01-06 05:53 +0000
Re: Blog "about python 3" Devin Jeanpierre <jeanpierreda@gmail.com> - 2014-01-05 00:00 -0800
Re: Blog "about python 3" Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-01-05 23:28 +1100
Re: Blog "about python 3" Chris Angelico <rosuav@gmail.com> - 2014-01-05 23:48 +1100
Re: Blog "about python 3" Roy Smith <roy@panix.com> - 2014-01-05 11:10 -0500
Re: Blog "about python 3" Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2014-01-05 13:51 -0500
Re: Blog "about python 3" David Hutto <dwightdhutto@gmail.com> - 2014-01-02 13:25 -0500
Re: Blog "about python 3" Terry Reedy <tjreedy@udel.edu> - 2014-01-02 13:37 -0500
Re: Blog "about python 3" Antoine Pitrou <solipsis@pitrou.net> - 2014-01-02 23:57 +0000
Re: Blog "about python 3" Robin Becker <robin@reportlab.com> - 2014-01-03 10:32 +0000
Re: Blog "about python 3" Robin Becker <robin@reportlab.com> - 2014-01-03 11:14 +0000
Re: Blog "about python 3" wxjmfauth@gmail.com - 2014-01-04 05:52 -0800
Re: Blog "about python 3" Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-01-05 13:41 +1100
Re: Blog "about python 3" Chris Angelico <rosuav@gmail.com> - 2014-01-05 13:54 +1100
Re: Blog "about python 3" wxjmfauth@gmail.com - 2014-01-05 02:39 -0800
Re: Blog "about python 3" Robin Becker <robin@reportlab.com> - 2014-01-03 11:37 +0000
Re: Blog "about python 3" Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-01-04 07:30 +0000
Re: Blog "about python 3" Johannes Bauer <dfnsonfsduifb@gmx.de> - 2014-01-05 13:14 +0100
Re: Blog "about python 3" Stefan Behnel <stefan_ml@behnel.de> - 2014-01-05 14:55 +0100
Re: Blog "about python 3" Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-01-05 13:10 +0000
Re: Blog "about python 3" Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-12-31 20:04 +1100
Re: Blog "about python 3" Devin Jeanpierre <jeanpierreda@gmail.com> - 2013-12-30 20:25 -0800
csiph-web