Mapping Hacks

Map Your Friend-of-a-Friend Network #99

Chapter 9, Mapping with Other People

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HACK

my @seen = ( );

my @files = (shift);

while (my $traverse = shift @files) {

print "reading $traverse\n";

my @objects;

eval {

@objects = Class::RDF->parse( uri => $traverse );

};

my @follow = grep {$_->rdfs::seeAlso} @objects;

foreach my $url (map {$_->rdfs::seeAlso->uri->value } @follow) {

my ($seen) = grep {$_ eq $url} @seen;

if (not $seen) {

push @files, $url;

push @seen, $url;

}

}

my @air = grep {$_->contact::nearestAirport} @objects;

foreach my $airport (@air) {

eval {

Class::RDF->parse( uri => $air_base.$airport->

airport::iataCode );

};

}

}

While it’s collecting files from the semantic web, this script is looking for

airports in the graphs it gets back. When it finds an IATA code property, it

looks it up at the service (e.g., http://jibbering.com/rdf/airports.1?BRS). This

returns a bigger RDF graph with the airport’s location, time zone, name, and

other features.

Jim Ley used a crawl of the FOAF web and an SVG world base map to draw

the “FOAF people map” shown in Figure 9-16; you can see the SVG version

along with other interesting FOAF experiments at http://www.jibbering.com/.

Making Your Own FOAF World Map

Featured in this book are a couple of different web services that will accept a

feed of points in RDF/XML or RSS and return an interactive map showing

the points plotted over a world map; one is worldKit ...