Popular recipes tagged "primes" but not "prime"http://code.activestate.com/recipes/tags/primes-prime/2017-04-25T11:44:27-07:00ActiveState Code RecipesBatch prime generator (Batch)
2017-04-25T11:44:27-07:00Antoni Gualhttp://code.activestate.com/recipes/users/4182514/http://code.activestate.com/recipes/580789-batch-prime-generator/
<p style="color: grey">
Batch
recipe 580789
by <a href="/recipes/users/4182514/">Antoni Gual</a>
(<a href="/recipes/tags/primes/">primes</a>).
Revision 3.
</p>
<p>Here is a radically differnt approach to generating primes in pure batch that overperforms everything else I have found . The idea comes from an exercise in Knuth's TAOCP Vol 3 page 617.</p>
Prime factors of an integer by Brent algorithm (Python)
2015-05-28T06:47:01-07:00Antoni Gualhttp://code.activestate.com/recipes/users/4182514/http://code.activestate.com/recipes/579049-prime-factors-of-an-integer-by-brent-algorithm/
<p style="color: grey">
Python
recipe 579049
by <a href="/recipes/users/4182514/">Antoni Gual</a>
(<a href="/recipes/tags/primes/">primes</a>, <a href="/recipes/tags/python/">python</a>).
</p>
<p>This recipe uses trial division to get factors below 1 milion then switches to Brent's algorithm to get bigger factors. No fast enough to break a RSA key :)</p>
Public Key Encryption (RSA) (Python)
2013-12-27T06:43:59-08:00Mohammad Taha Jahangirhttp://code.activestate.com/recipes/users/4188847/http://code.activestate.com/recipes/578797-public-key-encryption-rsa/
<p style="color: grey">
Python
recipe 578797
by <a href="/recipes/users/4188847/">Mohammad Taha Jahangir</a>
(<a href="/recipes/tags/encryption/">encryption</a>, <a href="/recipes/tags/inverse/">inverse</a>, <a href="/recipes/tags/multiplicative/">multiplicative</a>, <a href="/recipes/tags/primality_testing/">primality_testing</a>, <a href="/recipes/tags/primes/">primes</a>, <a href="/recipes/tags/publickey/">publickey</a>, <a href="/recipes/tags/rsa/">rsa</a>).
Revision 3.
</p>
<p>Simple code to create and use public/private keypairs. Accompanied by a rudimentary encoder.</p>
Find the nth prime in python (Python)
2013-01-06T20:23:21-08:00Captain DeadBoneshttp://code.activestate.com/recipes/users/4184772/http://code.activestate.com/recipes/578403-find-the-nth-prime-in-python/
<p style="color: grey">
Python
recipe 578403
by <a href="/recipes/users/4184772/">Captain DeadBones</a>
(<a href="/recipes/tags/primes/">primes</a>, <a href="/recipes/tags/prime_generator/">prime_generator</a>, <a href="/recipes/tags/prime_number/">prime_number</a>).
</p>
<p>This is a nth prime number generator in python that I put together for an article I wrote <a href="http://thelivingpearl.com/2013/01/06/how-to-find-prime-numbers-in-python/">How To Find Prime Numbers In Python</a></p>
Genreate x digits prime number in python, version 2 (Python)
2013-01-06T20:27:09-08:00Captain DeadBoneshttp://code.activestate.com/recipes/users/4184772/http://code.activestate.com/recipes/578405-genreate-x-digits-prime-number-in-python-version-2/
<p style="color: grey">
Python
recipe 578405
by <a href="/recipes/users/4184772/">Captain DeadBones</a>
(<a href="/recipes/tags/primes/">primes</a>, <a href="/recipes/tags/prime_generator/">prime_generator</a>).
</p>
<p>This is a prime number generator in python that I put together for an article I wrote <a href="http://thelivingpearl.com/2013/01/06/how-to-find-prime-numbers-in-python/">How To Find Prime Numbers In Python</a>. The script will generate a prime number of x digits, where x is less than 15. It might work for larger x, but it will take a while. </p>
Public Key Encryption (RSA) (Python)
2012-05-12T23:34:22-07:00Raymond Hettingerhttp://code.activestate.com/recipes/users/178123/http://code.activestate.com/recipes/577737-public-key-encryption-rsa/
<p style="color: grey">
Python
recipe 577737
by <a href="/recipes/users/178123/">Raymond Hettinger</a>
(<a href="/recipes/tags/encryption/">encryption</a>, <a href="/recipes/tags/inverse/">inverse</a>, <a href="/recipes/tags/multiplicative/">multiplicative</a>, <a href="/recipes/tags/primality_testing/">primality_testing</a>, <a href="/recipes/tags/primes/">primes</a>, <a href="/recipes/tags/publickey/">publickey</a>, <a href="/recipes/tags/rsa/">rsa</a>).
Revision 2.
</p>
<p>Simple code to create and use public/private keypairs. Accompanied by a rudimentary encoder.</p>
Even faster prime generator (C++)
2011-11-27T21:48:25-08:00Sumudu Fernandohttp://code.activestate.com/recipes/users/4180103/http://code.activestate.com/recipes/577966-even-faster-prime-generator/
<p style="color: grey">
C++
recipe 577966
by <a href="/recipes/users/4180103/">Sumudu Fernando</a>
(<a href="/recipes/tags/primes/">primes</a>, <a href="/recipes/tags/prime_generator/">prime_generator</a>).
</p>
<p>A very quick (segmented) sieve of Eratosthenes.</p>
<p>Takes ~6s on a midrange machine to hit all 50 847 534 primes less than 1 billion, ending with 999999937</p>
<p>If you want to actually <em>do</em> anything with every prime (beyond counting them), there are three places to add a statement doing whatever is necessary with "lastP" -- one at the top (handles the special case '2'), one in the middle (handles "small" primes which are actually used to sieve), and one at the bottom (handles "large" primes which merely survive sieving).</p>
<p>In principle one can use a function object as parameter to allow generic operations on the primes, so add that if you want more general-purpose code (perhaps I'll do that later)</p>
<p>For higher limits you need to switch to wider types and follow the commented guidelines for the constants. For a fixed limit, changing <code>B_SIZE</code> may affect performance so if needed tune it (profile as you go, of course!). But this will get quite slow if you go to much higher numbers.</p>
Faster prime generator (C++)
2011-10-08T23:26:24-07:00Mathijs Romanshttp://code.activestate.com/recipes/users/4179530/http://code.activestate.com/recipes/577899-faster-prime-generator/
<p style="color: grey">
C++
recipe 577899
by <a href="/recipes/users/4179530/">Mathijs Romans</a>
(<a href="/recipes/tags/primes/">primes</a>, <a href="/recipes/tags/prime_generator/">prime_generator</a>).
</p>
<p>The sieve of Eratosthenes implemented in C++. I noticed <a href="http://code.activestate.com/recipes/576559-fast-prime-generator/">another recipe</a> that could be improved upon, making it faster and a bit prettier.</p>
Fastest way to list all primes below N in python (Python)
2010-07-27T01:57:20-07:00robert.william.hankshttp://code.activestate.com/recipes/users/4174481/http://code.activestate.com/recipes/577331-fastest-way-to-list-all-primes-below-n-in-python/
<p style="color: grey">
Python
recipe 577331
by <a href="/recipes/users/4174481/">robert.william.hanks</a>
(<a href="/recipes/tags/fast/">fast</a>, <a href="/recipes/tags/fastest/">fastest</a>, <a href="/recipes/tags/math/">math</a>, <a href="/recipes/tags/numbers/">numbers</a>, <a href="/recipes/tags/numpy/">numpy</a>, <a href="/recipes/tags/primes/">primes</a>, <a href="/recipes/tags/python/">python</a>).
Revision 6.
</p>
<p>I was looking for a fast way to list all primes below n,
so far i came up to this with the numpy solution the fastest.
It does primes up to 10e6 in 15ms in my old machine,
and it is capable of reaching 10e9. </p>
A fast & memory-wise prime number generator up to N (Python)
2010-08-13T18:28:00-07:00robert.william.hankshttp://code.activestate.com/recipes/users/4174481/http://code.activestate.com/recipes/577357-a-fast-memory-wise-prime-number-generator-up-to-n/
<p style="color: grey">
Python
recipe 577357
by <a href="/recipes/users/4174481/">robert.william.hanks</a>
(<a href="/recipes/tags/fast/">fast</a>, <a href="/recipes/tags/numpy/">numpy</a>, <a href="/recipes/tags/primes/">primes</a>, <a href="/recipes/tags/prime_generator/">prime_generator</a>, <a href="/recipes/tags/prime_number/">prime_number</a>, <a href="/recipes/tags/python/">python</a>).
</p>
<p>Using python 2.6 & numpy.
This code was first posted <a href="http://stackoverflow.com/questions/2897297/speed-up-bitstring-bit-operations-in-python/2908512#2908512">here</a></p>
Infinite list of primes! Yay! (Python)
2010-07-20T04:05:00-07:00Alejandro Peraltahttp://code.activestate.com/recipes/users/4174433/http://code.activestate.com/recipes/577318-infinite-list-of-primes-yay/
<p style="color: grey">
Python
recipe 577318
by <a href="/recipes/users/4174433/">Alejandro Peralta</a>
(<a href="/recipes/tags/iterators/">iterators</a>, <a href="/recipes/tags/numbers/">numbers</a>, <a href="/recipes/tags/primes/">primes</a>).
</p>
<p>It's an iterator that returns prime numbers. </p>
<p>Got the idea from here: <a href="http://www.cs.hmc.edu/%7Eoneill/papers/Sieve-JFP.pdf" rel="nofollow">www.cs.hmc.edu/~oneill/papers/Sieve-JFP.pdf</a></p>
Simple primes generator (Python)
2009-11-04T06:52:06-08:00Maxime Fontenierhttp://code.activestate.com/recipes/users/4172150/http://code.activestate.com/recipes/576948-simple-primes-generator/
<p style="color: grey">
Python
recipe 576948
by <a href="/recipes/users/4172150/">Maxime Fontenier</a>
(<a href="/recipes/tags/any/">any</a>, <a href="/recipes/tags/generator/">generator</a>, <a href="/recipes/tags/numbers/">numbers</a>, <a href="/recipes/tags/primes/">primes</a>).
</p>
<p>Simple prime generator. </p>
<p>I write it as a sample usage of the any function.</p>
Sieve of Eratosthenes (Python)
2008-12-27T11:45:09-08:00Louis RIVIEREhttp://code.activestate.com/recipes/users/4035877/http://code.activestate.com/recipes/576596-sieve-of-eratosthenes/
<p style="color: grey">
Python
recipe 576596
by <a href="/recipes/users/4035877/">Louis RIVIERE</a>
(<a href="/recipes/tags/algorithms/">algorithms</a>, <a href="/recipes/tags/eratosthenes/">eratosthenes</a>, <a href="/recipes/tags/math/">math</a>, <a href="/recipes/tags/primes/">primes</a>).
Revision 3.
</p>
<p>Returns primes < n.</p>
Fast prime generator (C++)
2008-11-30T00:40:23-08:00Florian Mayerhttp://code.activestate.com/recipes/users/4165843/http://code.activestate.com/recipes/576559-fast-prime-generator/
<p style="color: grey">
C++
recipe 576559
by <a href="/recipes/users/4165843/">Florian Mayer</a>
(<a href="/recipes/tags/primes/">primes</a>, <a href="/recipes/tags/prime_generator/">prime_generator</a>).
Revision 2.
</p>
<p>This is the sieve of Eratosthenes implemented in C++.</p>
Prime look up program (Python)
2008-07-26T19:45:12-07:00Phil Huffmanhttp://code.activestate.com/recipes/users/4165783/http://code.activestate.com/recipes/576380-prime-look-up-program/
<p style="color: grey">
Python
recipe 576380
by <a href="/recipes/users/4165783/">Phil Huffman</a>
(<a href="/recipes/tags/algorithm/">algorithm</a>, <a href="/recipes/tags/primes/">primes</a>).
</p>
<p>Finds the nth prime without using a sieve algorithm. </p>