primefac fork

This is fork of primefac Module.

• use a fast function, in modinv
• use ecpy for faster ECM
• Implement fermat factorization

License

This software released under the MIT License.

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Below is the original documentation for the primefac module.

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primefac version 1.1

This is a module and command-line utility for factoring integers. As a module, we provide a primality test, several functions for extracting a non-trivial factor of an integer, and a generator that yields all of a number's prime factors (with multiplicity). As a command-line utility, this project aims to replace GNU's factor command with a more versatile utility --- in particular, this utility can operate on arbitrarily large numbers, uses multiple cores in parallel, uses better algorithms, handles input in reverse Polish notation, and can be tweaked via command-line flags.

What's New in v1.1

Bugfixes:

• In version 1.0.0, when neither gmpy nor gmpy2 could be imported, legendre was not defined properly and errors were thrown. This is fixed in version 1.1.

New features:

• A new function factorint is added with the same argument structure as the primefac generator, minus the verbose option. This collates primefac's output into a dict with the prime factors as the keys and their multiplicities as the data. For example, factorint(5040) returns {2:4, 3:2, 5:1, 7:1}.

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