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.
COPYRIGHT AND LICENSE
Copyright (C) 2016 John M. Gamble. All rights reserved. This program is
free software; you can redistribute it and/or modify it under the same
terms as Perl itself.