NAME

SVG::Timeline::Genealogy - Create genealogical timelines in SVG

SYNOPSIS

    use SVG::Timeline::Genealogy

    my $tl = SVG::Timeline::Genealogy->new;

    $tl->add_person({
      ahnen => 1,
      start => 1975,
      text  => 'You',
    });

    $tl->add_person({
      anhen => 2,
      start => 1950,
      end   => 1980,
      text  => 'Your Father',
    });

    $tl->add_person({
      anhen => 3,
      start => 1950,
      text  => 'Your Mother',
    });

    print $tl->draw;

DESC

This module allows you to easily create SVG documents that represent genealogical timelines.

The module is a subclass of SVG::Timeline and this documentation should be read in conjunction with the documentation for that module. SVG::Timeline deals with events, in this subclass, events have been renamed to people.

When I say "genealogical timeline", I mean an ancestor chart. This is a diagram which shows the ancestors of a person. Each person on the timeline is represented by a bar which shows the years they were alive. The position and colour of the bars show the relationships between the people in the timeline.

In this module, people have all of the same attributes as events do in SVG::Timeline, but there is one extra attribute (called "ahnen") which might need some explanation.

The term "ahnen" is short for "Anhnentafel Number". This is a number that can be given to people in a genealogical system in order to represent relationships between them.

If you have the Ahnentafel number of 1, then your father is 2 and mour mother is 3. You father's parents are 4 and 5 and your mother's are 6 and 7. These numbers have some interesting properties. If a person's number is $x, then their father will be 2 * $x and their mother will be 2 * $x + 1. Also, this the exception of person 1 (who can be of either sex), all men have even Ahnentafel numbers and all women have odd ones.

All of which means that if you give us the Ahnentafel number for the people you add to the chart (and you have to - it's a required attribute), then we can work out all the relationships between the people.

METHODS AND ATTRIBUTES

You'll also need to see the documentation for SVG::Timeline. This document only includes details of the changed and extra methods and attributes.

calculate_indexes()

The order that people appear in the chart isn't controlled by the order that they are added but, rather, their Ahnentafel number. That means that every time a new person is added, the indexes need to be recalculated. This method does that. You should never need to call it.

max_generation

Returns the maximum number of generations that the timeline contains.

events_in_timeline

Returns the number of events expected in the timeline. This isn't just the number of events (i.e. people) that have been added to the timeline. In genealogy, we often don't know some of our ancestry (children being born out of wedlock is far more common than you might think) and we need to leave space for those people or the chart will look wrong.

So we calculate the number of expected people from the number of generations in the timeline.

AUTHOR

Dave Cross <dave@perlhacks.com>

COPYRIGHT AND LICENCE

Copyright (c) 2017, Magnum Solutions Ltd. All Rights Reserved.

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.