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Old 2019-12-31, 16:39   #177
gjhiggins
 
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Quote:
Originally Posted by MJansen View Post
I was trying to follow your instructions and looked at the illustrated guide, but must have missed the part you refer to in step 1: clone your Github fork locally and change directory to the clone. I have to admit that I am totally clueless as to what that implies, could you help out?
Apologies, I intended to include a couple of pointers to documentation of creating a repository on GitHub: https://www.wikihow.com/Clone-a-Repository-on-Github and https://help.github.com/en/github/cr...g-a-repository

Quote:
I made a text file in the format you showed at the illustrated guide (136098,0,C,?,P,Toni_Key,2016,16.37,3610,"1500031*8431#/41910 - 97126")

The text file has 456 improvements on the data Tom published last (august 12th 2019 if I am correct). BTW this does not mean sombody else has improved sooner on these gaps. But this data can be used for testing.
When pasted into or uploaded to the web gui converter (https://primegap-list-project.github.io/nicely-to-sql/), that text produces the expected results. There are a couple of entries that have subsequently been improved - they are preserved in the output as commented-out lines of SQL.

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Further, where can I find SQLlite3? Do you have a link? And what does dump the database mean? And pushing changes? I apologize for the noob questions, but this is all new to me and not very intuitive.
Again, apologies, mea culpa.

The main sqlite website: https://sqlite.org/index.html and documentation of the command-line shell: https://sqlite.org/cli.html

There is a GUI SQL browser: https://sqlitebrowser.org/ but be prepared for a significant delay when reading SQL source (i.e. allgaps.sql) - it reads a SQLite db (e.g. allgaps.db) much faster. Given that the set of required operations is very contained, I assume the faster command line shell would be appreciated more than the inessential GUI - but the GUI is quite nice to use for ad hoc explorations of the data set.

Cheers

Graham
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Old 2020-01-02, 09:51   #178
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Originally Posted by storm5510 View Post

I have started my own search for 2000 using code I wrote. I have it filtering for anything GEQ 500, just so I can see it move on the screen once in a while. It is not at all efficient so it may take a while. I am in no hurry.
The split of interest between gaps of length 1-2000 and 2000 and above is totally arbitrary. The next few "pages" of records are shown at

https://faculty.lynchburg.edu/~nicely/index.html#TPG

So your gap of 2000 needs to be smaller than the current record

2000 C?C Spielaur 2017 29.96 29 99000033712000137027043172639

Maybe your efforts would be better aimed at the record for 2002

2002 C?C Spielaur 2013 26.41 33 824742086414264032043746981329337

The level of effort for this would be approx. 1/10th of that required to beat 2000.

A good way to tackle this would be to look at offsets to small primorials - you can read more on those here

https://www.mersenneforum.org/showthread.php?t=23753

I set 47 records for small gaps using 2200 as an offset.
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Old 2020-01-02, 13:28   #179
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Quote:
Originally Posted by robert4444uk
So your gap of 2000 needs to be smaller than the current record
By this, I believe you mean the size of the prime numbers used to find it. The simple way would be to start at 1e28. 2^94 is somewhat farther up, Both are 29 digits. I am not exactly geared in to find anything of a fixed size. I simply watch for the largest I see on the screen at given intervals when they are briefly displayed.

Quote:
Originally Posted by robert4444uk
The split of interest between gaps of length 1-2000 and 2000 and above is totally arbitrary. The next few "pages" of records are shown at

https://faculty.lynchburg.edu/~nicely/index.html#TPG
Wow! I had no idea how large this had become. I was stunned by just looking at the first few pages. Seeing this makes me feel like I have been running a fools' errand.

Quote:
Originally Posted by robert4444uk
Maybe your efforts would be better aimed at the record for 2002

2002 C?C Spielaur 2013 26.41 33 824742086414264032043746981329337

The level of effort for this would be approx. 1/10th of that required to beat 2000.
The large prime above is 33 digits long. I started at 33 digits Just slightly below 2^108.

Quote:
Originally Posted by robert4444uk
I set 47 records for small gaps using 2200 as an offset.
An offset from what?

I need to stop for a while and think about what I am doing and how it is being done. I definitely want to participate. At what level, I am not sure at this point. I can go way up in size. The cost is performance.
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Old 2020-01-02, 17:22   #180
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Quote:
Originally Posted by storm5510 View Post

An offset from what?
The theory is in the first post at this thread.

https://www.mersenneforum.org/showpo...99&postcount=1

The offset X is an amount added or subtracted to a*p#/q, where p#/q is a deficient primorial and a an integer.

By careful choice of offset, the number of integers around a*p#/q+/-X that are divisible by small primes can be made to be large, and hence the chance of a large gap is increased.

ATH's software referred to in the post provides that careful choice.
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Old 2020-01-03, 00:36   #181
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Quote:
Originally Posted by robert44444uk
Maybe your efforts would be better aimed at the record for 2002

2002 C?C Spielaur 2013 26.41 33 824742086414264032043746981329337

The level of effort for this would be approx. 1/10th of that required to beat 2000.
I will give this a go. There is not a sure way to determine exactly where the individual noted above started. It is somewhere above 2^119 (664613997892457936451903530140172256). I will simply need to start somewhere below his end prime.

After much asking, I sent my poor program to a member friend on a dedicated programming forum. He rewrote it using a GMP library and a lot of pointers. There is not much resemblance to what I sent. What he sent back is incredibly faster than what I had. At least 10x. Maybe 15x.
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Old 2020-01-03, 23:34   #182
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It looks like I am dead-in-the-water with this where my new program is concerned. I wanted to run it on my HP with Windows 7 Pro x64. It will not run there after being revised.

So, I am in the market for something which will do this job. Any suggestions?
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Old 2020-01-04, 00:20   #183
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Ubuntu is the least-scary of the Linux flavors for a new user, IMO.
If your machine is reasonably modern, say 8GB of RAM or more, you can just run a virtual machine with linux inside, test the program(s) and OS "feel" to see how it goes for you, and perhaps once accustomed to it ditch windows entirely and run Linux. I tried virtualbox for this purpose on an older quad-core laptop, with decent results.

Desktops are simpler, lacking power management functions, and thus are a bit easier to wipe windows in favor of linux flavors.
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Old 2020-01-04, 00:56   #184
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Originally Posted by VBCurtis View Post
...Desktops are simpler, lacking power management functions, and thus are a bit easier to wipe windows in favor of linux flavors.
The HP is no longer Linux. That particular HD failed. So, I replugged the Windows 7 Pro drive. Ubuntu has too steep of a leaning curve for this old brain. So, I will not worry about it. I need to go with what I know.
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Old 2020-01-25, 06:20   #185
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As I understand it the longest maximal prime gap known is of length 1550, following P20 = 18361375334787046697. Is this correct? How far has this been searched/what are the current search limits?
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Old 2020-01-25, 12:00   #186
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Originally Posted by CRGreathouse View Post
As I understand it the longest maximal prime gap known is of length 1550, following P20 = 18361375334787046697. Is this correct? How far has this been searched/what are the current search limits?
Take a look at the link below. I was a bit stunned by the magnitude of where this is now.

https://faculty.lynchburg.edu/~nicely/index.html#TPG
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Old 2020-01-25, 12:32   #187
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Quote:
Originally Posted by CRGreathouse View Post
As I understand it the longest maximal prime gap known is of length 1550, following P20 = 18361375334787046697. Is this correct? How far has this been searched/what are the current search limits?
That appears to be correct. No gap of length greater than 1550 has been found below 264.

ATH has searched up to 264+1015 or thereabouts, see this post:
https://www.mersenneforum.org/showpo...0&postcount=69
I'm not aware of any further coordinated efforts.

Last fiddled with by mart_r on 2020-01-25 at 12:35 Reason: modified URL
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