++ed by:
ARODLAND TSIBLEY

2 PAUSE users

Steve Troxel

NAME

Data::DownSample::LargestTriangleThreeBuckets

VERSION

Version 1.00

DESCRIPTION

Implements a downsample technique known as Largest Triangle Three Buckets as defined in Sveinn Steinarsson MS thesis.

http://skemman.is/stream/get/1946/15343/37285/3/SS_MSthesis.pdf

The idea is to downsample a data set without losing the visual character of the plotted data. The technique draws on ideas in cartographic generalization or polyline simplification. This technique is often useful in client-server applications such as webserver-browser where the length of the data far exceeds the pixels available to plot. Reducing the data size significantly speeds up data transfer and rendering time.

SYNOPSIS

use Data::DownSample::LargestTriangleThreeBuckets;

my $lttb = new Data::DownSample::LargestTriangleThreeBuckets( {threshold=>1000} );

my $data_src = [ [1,2], [2,3], [3,4], [4,5], ... ]; # <-- load your data source here as reference to a list of a list

my $data_sampled = $lttb->lttb($data_src);

SUBROUTINES/METHODS

lttb()

my $data_sampled = $lttb->lttb($data_src);

Also can overwrite the class threashold variable such as

my $data_sampled = $lttb->lttb($data_src,20000);

This function is an optimized version of the algorithm given in Sveinn Steinarsson paper. Several of the math operation are factored out of the loops and it executes better than 33% faster.

lttb_ref()

my $data_sampled = $lttb->lttb_ref($data_src);

The reference function implimentation of the algorithm given in Sveinn Steinarsson paper and used to verify that the optimized version is giving correct results.

AUTHOR

Steve Troxel, <troxel at perlworks.com>

BUGS

Please report any bugs or feature requests to bug-data-downsample-largesttrianglethreebuckets at rt.cpan.org, or through the web interface at http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Data-DownSample-LargestTriangleThreeBuckets. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.

SUPPORT

You can find documentation for this module with the perldoc command.

    perldoc Data::DownSample::LargestTriangleThreeBuckets

You can also look for information at:

LICENSE AND COPYRIGHT

Copyright 2016 Steve Troxel.

This program is free software; you can redistribute it and/or modify it under the terms of the the Artistic License (2.0). You may obtain a copy of the full license at:

http://www.perlfoundation.org/artistic_license_2_0

Any use, modification, and distribution of the Standard or Modified Versions is governed by this Artistic License. By using, modifying or distributing the Package, you accept this license. Do not use, modify, or distribute the Package, if you do not accept this license.

If your Modified Version has been derived from a Modified Version made by someone other than you, you are nevertheless required to ensure that your Modified Version complies with the requirements of this license.

This license does not grant you the right to use any trademark, service mark, tradename, or logo of the Copyright Holder.

This license includes the non-exclusive, worldwide, free-of-charge patent license to make, have made, use, offer to sell, sell, import and otherwise transfer the Package with respect to any patent claims licensable by the Copyright Holder that are necessarily infringed by the Package. If you institute patent litigation (including a cross-claim or counterclaim) against any party alleging that the Package constitutes direct or contributory patent infringement, then this Artistic License to you shall terminate on the date that such litigation is filed.

Disclaimer of Warranty: THE PACKAGE IS PROVIDED BY THE COPYRIGHT HOLDER AND CONTRIBUTORS "AS IS' AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES. THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT ARE DISCLAIMED TO THE EXTENT PERMITTED BY YOUR LOCAL LAW. UNLESS REQUIRED BY LAW, NO COPYRIGHT HOLDER OR CONTRIBUTOR WILL BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING IN ANY WAY OUT OF THE USE OF THE PACKAGE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.