Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > comp.os.linux.advocacy > #383618
| From | deplorable owl <owl@rooftop.invalid> |
|---|---|
| Newsgroups | comp.os.linux.advocacy |
| Subject | Re: Where are you, sdb? I have something fun for your little morons to try |
| Date | 2016-12-11 00:02 +0000 |
| Organization | O.W.L. |
| Message-ID | <aybudaoc993.ag@rooftop.invalid> (permalink) |
| References | (7 earlier) <o2g7a6$7sj$1@news.albasani.net> <ahjgcks002.gqe@rooftop.invalid> <o2ho5i$n47$3@dont-email.me> <ahjgob040.ae@rooftop.invalid> <o2i132$ll7$1@dont-email.me> |
DFS <nospam@dfs.com> wrote: > On 12/10/2016 03:44 PM, deplorable owl wrote: >> DFS <nospam@dfs.com> wrote: >>> On 12/10/2016 02:56 PM, deplorable owl wrote: >>>> Melzzzzz <Melzzzzz@zzzzz.com> wrote: >>>>> On 10/12/16 07:25 AM, deplorable owl wrote: >>>>>> Melzzzzz <Melzzzzz@zzzzz.com> wrote: >>>>>> >>>>>> BTW, what's the proper approach to randomizing such a huge number of >>>>>> values? (A large enough pool of seconds so that randoms would have >>>>>> a good chance of falling on 100,000 different days). >>>>>> >>>>>> >>>>> You don't have to just filter out dupes ;p >>>>> It is not needed to have 100000k uniques at all. >>>> >>>> Yeah, but filtering is just to get uniques. Say you want 100000 unique >>>> days using random second values, minimizing dups and generating exactly >>>> 100000 values, how would you approach that? >>> >>> >>> 1. Write 100K random dates to a table with a PK >>> >>> 2. Count the rows - it would very likely be less than 100K >>> >>> 3. Write 1 more random at a time and test the row count after every >>> INSERT, until you hit exactly 100K. >>> >>> 4. Read them back into an array (and shuffle it if you need it in >>> random order)? >>> >> >> It's not really about dates -- that's just the application here -- but >> about the number range. The problem is generating the random seconds. >> 100,000 days is 8.64 billion seconds. How to get a random generation, >> minimizing dups, while generating exactly 100,000 values (not after >> stripping dups, but for exactly 100,000 iterations), over such a huge >> range when rand() and random() work over a range of 0-RAND_MAX, which >> is a range of 0-2.14 billion. > > > You don't need to generate 8,640,000,000 randoms at once. > > Gen 100K randoms for the days and 100K randoms for the seconds, then > concatenate them. > > rand1: 20090615 > rand2: 134530 > > becomes 2009-06-15 13:45:30 > Which is still a day value of 20090615. 86400 different seconds values will fall on that day, hence the huge number of seconds values required for 100000 unique days. anon@lowtide:~/code/dfsdates$ date -d "2009-06-15 13:45:30" +%s 1245087930 anon@lowtide:~/code/dfsdates$ date -d "2009-06-15 4:10:12" +%s 1245053412 anon@lowtide:~/code/dfsdates$ date -d @1245087930 +%d-%b-%Y 15-Jun-2009 anon@lowtide:~/code/dfsdates$ date -d @1245053412 +%d-%b-%Y 15-Jun-2009 anon@lowtide:~/code/dfsdates$ You can easily cheat and generate all seconds values sequentially over a 273 year period, then enter them modulo 86400 into an array of 100000, but that's an *ordered* array, and what you want is randoms. (Randomizing the 100000 is not a problem, but that avoids the challenge). Generating the random seconds that give 100000 unique *day* values (well, fewest dups) for those seconds is the difficulty. Again, I don't care about this as a "date" problem. I want to know the best approach for randomizing over a huge range (far exceeding RAND_MAX) with minimal dups.
Back to comp.os.linux.advocacy | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-07 12:27 -0500
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-07 19:52 +0000
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-07 21:28 -0500
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-08 05:52 +0000
Re: Where are you, sdb? I have something fun for your little morons to try chrisv <chrisv@nospam.invalid> - 2016-12-08 07:02 -0600
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-08 09:02 -0500
Re: Where are you, sdb? I have something fun for your little morons to try Adlbifhr Mjduhgfks <am@random.us> - 2016-12-08 00:32 +0000
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-07 21:48 -0500
Re: Where are you, sdb? I have something fun for your little morons to try Adlbifhr Mjduhgfks <am@random.us> - 2016-12-08 14:17 +0000
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-08 11:00 -0500
Re: Where are you, sdb? I have something fun for your little morons to try Steve Carroll <fretwizzer@gmail.com> - 2016-12-08 09:13 -0800
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-08 18:41 -0500
Re: Where are you, sdb? I have something fun for your little morons to try Steve Carroll <fretwizzer@gmail.com> - 2016-12-08 17:32 -0800
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-08 21:12 -0500
Cartoons are easier to read than the Wall Street Journal. Jeff-Relf.Me <@.> - 2016-12-08 20:16 -0800
Re: Where are you, sdb? I have something fun for your little morons to try Steve Carroll <fretwizzer@gmail.com> - 2016-12-09 09:03 -0800
Re: Where are you, sdb? I have something fun for your little morons to try Adlbifhr Mjduhgfks <am@random.us> - 2016-12-08 15:49 +0000
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-08 11:00 -0500
Re: Where are you, sdb? I have something fun for your little morons to try Adlbifhr Mjduhgfks <am@random.us> - 2016-12-08 16:24 +0000
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-08 18:43 -0500
Only _results_ matter; i.e.: What does it do ? Jeff-Relf.Me <@.> - 2016-12-08 19:45 -0800
Re: Only _results_ matter; i.e.: What does it do ? flatfish+++ <flatfish@linuxmail.org> - 2016-12-08 22:50 -0500
I don't need the source code. Jeff-Relf.Me <@.> - 2016-12-08 20:39 -0800
Re: I don't need the source code. flatfish+++ <flatfish@linuxmail.org> - 2016-12-08 23:48 -0500
I'm hard to copy, thank God. Jeff-Relf.Me <@.> - 2016-12-08 22:30 -0800
Re: I'm hard to copy, thank God. flatfish+++ <flatfish@linuxmail.org> - 2016-12-09 01:54 -0500
Re: I'm hard to copy, thank God. Steve Carroll <fretwizzer@gmail.com> - 2016-12-09 12:30 -0800
Re: I don't need the source code. Poutnik <poutnik4nntp@gmail.com> - 2016-12-09 07:12 +0100
Re: I don't need the source code. flatfish+++ <flatfish@linuxmail.org> - 2016-12-09 01:15 -0500
Re: I don't need the source code. Poutnik <poutnik4nntp@gmail.com> - 2016-12-09 07:27 +0100
Re: I don't need the source code. flatfish+++ <flatfish@linuxmail.org> - 2016-12-09 01:44 -0500
Usenet is not CraigsList nor WikiPedia, Reddit. Jeff-Relf.Me <@.> - 2016-12-08 23:00 -0800
Re: Usenet is not CraigsList nor WikiPedia, Reddit. flatfish+++ <flatfish@linuxmail.org> - 2016-12-09 02:12 -0500
If/When Cola is being honest, they don't think MicroSoft is "Evil". Jeff-Relf.Me <@.> - 2016-12-08 23:56 -0800
Re: Usenet is not CraigsList nor WikiPedia, Reddit. Poutnik <poutnik4nntp@gmail.com> - 2016-12-09 08:16 +0100
Usually, the __DEFAULT__ "Subject:" line isn't best. Jeff-Relf.Me <@.> - 2016-12-08 22:53 -0800
Re: Usually, the __DEFAULT__ "Subject:" line isn't best. Poutnik <poutnik4nntp@gmail.com> - 2016-12-09 08:19 +0100
Please lookup the word "Default". Jeff-Relf.Me <@.> - 2016-12-08 23:31 -0800
Re: Please lookup the word "Default". Poutnik <poutnik4nntp@gmail.com> - 2016-12-09 08:42 +0100
The parent post. -- Re: Please lookup the word "Default". Jeff-Relf.Me <@.> - 2016-12-09 00:12 -0800
Re: The parent post. -- Re: Please lookup the word "Default". Poutnik <poutnik4nntp@gmail.com> - 2016-12-09 11:28 +0100
Threads branch like a tree, SubTopics sprout. Jeff-Relf.Me <@.> - 2016-12-09 03:35 -0800
Re: Threads branch like a tree, SubTopics sprout. Poutnik <poutnik4nntp@gmail.com> - 2016-12-09 16:18 +0100
Re: The parent post. -- Re: Please lookup the word "Default". moroney@world.std.spaamtrap.com (Michael Moroney) - 2016-12-09 15:05 +0000
I want details, Michael Moroney. Jeff-Relf.Me <@.> - 2016-12-09 07:18 -0800
Re: I want details, Michael Moroney. Steve Carroll <fretwizzer@gmail.com> - 2016-12-09 10:38 -0800
Re: I want details, Michael Moroney. moroney@world.std.spaamtrap.com (Michael Moroney) - 2016-12-10 04:03 +0000
I never had to deal with such problems. Jeff-Relf.Me <@.> - 2016-12-09 21:15 -0800
Re: I never had to deal with such problems. moroney@world.std.spaamtrap.com (Michael Moroney) - 2016-12-11 01:50 +0000
Re: The parent post. -- Re: Please lookup the word "Default". chrisv <chrisv@nospam.invalid> - 2016-12-09 09:37 -0600
Re: The parent post. -- Re: Please lookup the word "Default". moroney@world.std.spaamtrap.com (Michael Moroney) - 2016-12-09 20:32 +0000
Re: I don't need the source code. chrisv <chrisv@nospam.invalid> - 2016-12-09 06:39 -0600
Re: I don't need the source code. Poutnik <poutnik4nntp@gmail.com> - 2016-12-09 16:19 +0100
Re: I don't need the source code. Silver Slimer <.m@nsn.s> - 2016-12-09 11:51 -0500
Re: I don't need the source code. flatfish+++ <flatfish@linuxmail.org> - 2016-12-09 12:07 -0500
Re: I don't need the source code. Silver Slimer <.m@nsn.s> - 2016-12-09 12:22 -0500
Re: I don't need the source code. flatfish+++ <flatfish@linuxmail.org> - 2016-12-09 12:28 -0500
Re: I don't need the source code. moroney@world.std.spaamtrap.com (Michael Moroney) - 2016-12-09 17:52 +0000
I only have time to read a few select authors, sorry. Jeff-Relf.Me <@.> - 2016-12-09 10:05 -0800
Re: I don't need the source code. chrisv <chrisv@nospam.invalid> - 2016-12-09 12:26 -0600
Re: I don't need the source code. Silver Slimer <.m@nsn.s> - 2016-12-09 14:06 -0500
Re: I don't need the source code. Chris Ahlstrom <OFeem1987@teleworm.us> - 2016-12-09 19:56 -0500
Re: I don't need the source code. Silver Slimer <.m@nsn.s> - 2016-12-10 09:23 -0500
Re: Only _results_ matter; i.e.: What does it do ? fr314159@gmail.com - 2016-12-09 07:17 -0800
Re: Only _results_ matter; i.e.: What does it do ? DFS <nospam@dfs.com> - 2016-12-12 18:54 -0500
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-12 18:39 -0500
Re: Where are you, sdb? I have something fun for your little morons to try Melzzzzz <mel@zzzzz.com> - 2016-12-09 03:38 +0100
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-09 19:00 +0000
Re: Where are you, sdb? I have something fun for your little morons to try Melzzzzz <mel@zzzzz.com> - 2016-12-10 00:33 +0100
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-10 05:24 +0000
Re: Where are you, sdb? I have something fun for your little morons to try Melzzzzz <Melzzzzz@zzzzz.com> - 2016-12-10 06:54 +0100
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-10 06:25 +0000
Re: Where are you, sdb? I have something fun for your little morons to try Melzzzzz <Melzzzzz@zzzzz.com> - 2016-12-10 07:28 +0100
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-10 19:56 +0000
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-10 15:19 -0500
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-10 15:23 -0500
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-10 20:44 +0000
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-10 17:55 -0500
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-11 00:02 +0000
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-10 19:39 -0500
C/CPP's "srand( int Seed )" generates an array of (PseudoRandom) int's. Jeff-Relf.Me <@.> - 2016-12-10 23:09 -0800
Re: C/CPP's "srand( int Seed )" generates an array of (PseudoRandom) int's. deplorable owl <owl@rooftop.invalid> - 2016-12-11 07:23 +0000
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-10 19:56 -0500
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-10 20:07 -0500
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-11 04:07 +0000
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-11 00:18 -0500
Re: Where are you, sdb? I have something fun for your little morons to try Melzzzzz <mel@zzzzz.com> - 2016-12-11 03:40 +0100
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-11 04:00 +0000
Re: Where are you, sdb? I have something fun for your little morons to try Melzzzzz <Melzzzzz@zzzzz.com> - 2016-12-11 05:08 +0100
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-11 04:27 +0000
Re: Where are you, sdb? I have something fun for your little morons to try Melzzzzz <Melzzzzz@zzzzz.com> - 2016-12-11 05:58 +0100
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-11 05:55 +0000
Re: Where are you, sdb? I have something fun for your little morons to try Melzzzzz <Melzzzzz@zzzzz.com> - 2016-12-11 07:11 +0100
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-11 06:49 +0000
Re: Where are you, sdb? I have something fun for your little morons to try Melzzzzz <mel@zzzzz.com> - 2016-12-11 07:52 +0100
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-11 07:09 +0000
Re: Where are you, sdb? I have something fun for your little morons to try Melzzzzz <Melzzzzz@zzzzz.com> - 2016-12-11 08:23 +0100
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-11 07:37 +0000
Re: Where are you, sdb? I have something fun for your little morons to try Melzzzzz <Melzzzzz@zzzzz.com> - 2016-12-11 08:40 +0100
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-11 09:05 +0000
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-10 19:41 +0000
Re: Where are you, sdb? I have something fun for your little morons to try Melzzzzz <mel@zzzzz.com> - 2016-12-10 20:48 +0100
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-10 20:06 +0000
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-10 10:32 -0500
Re: Where are you, sdb? I have something fun for your little morons to try Melzzzzz <mel@zzzzz.com> - 2016-12-10 16:40 +0100
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-10 11:03 -0500
Re: Where are you, sdb? I have something fun for your little morons to try Steve Carroll <fretwizzer@gmail.com> - 2016-12-10 09:26 -0800
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-10 12:38 -0500
Re: Where are you, sdb? I have something fun for your little morons to try Steve Carroll <fretwizzer@gmail.com> - 2016-12-10 09:52 -0800
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-10 13:01 -0500
Re: Where are you, sdb? I have something fun for your little morons to try Steve Carroll <fretwizzer@gmail.com> - 2016-12-10 10:06 -0800
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-10 19:38 +0000
Re: Where are you, sdb? I have something fun for your little morons to try DFS <nospam@dfs.com> - 2016-12-10 19:55 -0500
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-10 19:33 +0000
Re: Where are you, sdb? I have something fun for your little morons to try deplorable owl <owl@rooftop.invalid> - 2016-12-10 20:00 +0000
csiph-web