Algorithm::Networksort version 2.02

"I've got to sort this out. ... There must be a list somewhere
of the ones these bastards were nicking, and I wish I had it.  I
would make it even money that the name of the murderer is on it.
Would you?"

"No."

"Anything to be contrary. Why not?"

"You haven't done enough sorting, Mr. Cramer."
    The Golden Spiders, by Rex Stout (1953, ch. 13)

With version 2.00, sorting networks are now much easier to use objects. If your code is not ready for this change, stick with version 1.30, which will stay present on CPAN until at least 2017.

This module will create sorting networks, a sequence of comparisons that do not depend upon the results of prior comparisons.

Since the sequences and their order never change, they can be very useful if deployed in hardware, or used in software with a compiler that can take advantage of parallelism. However a network cannot be used as a generic sort like quicksort, as the arrangement of the comparisons is fixed according to the number of elements to be sorted.

There are several algorithms to generate sorting networks. This module has four of them: Bose and Nelson's, Hibbard's, Batcher's Merge Exchange, Batcher's Bitonic, Batcher's Odd-Even Merge, as well as Odd-Even Transposition, Balanced, and Bubble (thanks to Doug Hoyte, who contributed code for the last five sorts, the last three of which are more for comparison and teaching purposes).

It also has networks that were found to be superior in comparison count or parallel count ('depth') to those generated automatically by these algorithms (thanks to Morwenn, who contributed to this).

There is a flexible formatting function that will allow you to print out your network in many ways (see documentation). There is also a graphical output function that will return the network in an encapsulated postscript, SVG, or text form.

INSTALLATION

The usual way. Unpack the archive: gzip -d Algorithm-Networksort-2.02.tar.gz tar xvf Algorithm-Networksort-2.02.tar

Go into the resulting directory, and type: perl Build.PL Build

Run the tests: Build test

Install the module: Build install

MORE ON TESTING

With the addition of 'best' networks for sizes 18 and 22, the testing time went from 'lengthy' to 'intolerable for unsuspecting CPAN testers'. Consequently, the sorting tests now have an upper limit of 10 for normal testing. This size goes up to 17 if the environment variable AUTHOR_TESTING is set (and the size 12 and up 'best' networks are also tested).

If you want to have the full testing experience, I've provided a switch that will automatically do all this for you. Run the tests with

Build test --Testlong

and the full suite will run (and depending on your machine, you may have time to go out and get lunch). If you want to run only a single test file, then the Module-Build switch '--test_files' can select that file for you:

Build test --test_files=t/best.t --Testlong

Note that the '--Testlong' switch comes last.

jgamble / Algorithm-Networksort

readme

Algorithm::Networksort version 2.02