FUN WITH MAPS & PHP
Chris Shiflett — @shiflett — shiflett.org

Web aficionado, author, blogger, soccer player, bike
Who am I? rider, beer drinker, music lover, Brooklynite.

0. Landice
Dettifoss

TRAVELOG
Tag everything
– #landice
Blog
– every night
Timeline Visualizations
– maps?
A!regate and Plot
– photos, tweets, videos, etc.

1. Research
Sjónarsker

EXISTING TOOLS
GPS
– Garmin GPS 60CSx
GPSBabel
– gpsbabel.org
EveryTrail
– everytrail.com
HoudahGeo
– houdah.com/houdahGeo/

2. Reykjavík
Stóra-Víti

3. Photos
Kirkjufell

<?xml version="1.0" encoding="UTF-8"?>
<gpx
version="1.0"
creator="GPSBabel - http://gpsbabel.org/"
xmlns:xsi="http://w3.org/2001/XMLSchema-instance"
xmlns="http://topografix.com/GPX/1/0"
xsi:schemaLocation="http://topografix.com/GPX/1/0
http://topografix.com/GPX/1/0/gpx.xsd">
<time>2009-06-14T23:52:23Z</time>
<bounds minlat="64.143006038" minlon="-21.955686333"
maxlat="64.153455254" maxlon="-21.915427381"/>
<trk>
<name>14-JUN-09 01</name>
<number>1</number>
<trkseg>
<trkpt lat="64.150910676" lon="-21.946594650">
<ele>13.115112</ele>
<time>2009-06-14T21:01:25Z</time>
</trkpt>
<trkpt lat="64.150785115" lon="-21.945423950">
<ele>13.595825</ele>
<time>2009-06-14T21:02:08Z</time>
</trkpt>
</trkseg>
</trk>
</gpx>

PARSING GPX
$xml = simplexml_load_file('trip.gpx');
foreach($xml->trk as $part) {
foreach ($part->trkseg->trkpt as $point) {
/*
$point['lat']
$point['lon']
$point->time
$point->ele
*/
}
}

4. Maps
Bláa lónið

Garmin GPS 60CSx Nikon D300
HoudahGeo

EVERYTRAIL

$query = $db->prepare("SELECT lat, lon
FROM points
WHERE timestamp > '$start'
AND timestamp < '$end'
ORDER BY timestamp");
$query->execute();
$points = array();
while ($row = $query->fetch()) {
$points[] = array('lat' => $row['lat'],
'lon' => $row['lon']);
}
$trip['points'] = $points;
$json = json_encode($trip);
file_put_contents("/tmp/landice-$day.json", $json);

// FIXME: http://tr.im/selectclosest
$sql = "SELECT lat, lon, elevation,
ABS(timestamp - :timestamp) as distance
FROM points
ORDER BY distance
LIMIT 1"
$select = $this->db->prepare($sql);
foreach ($this->photos as $photo) {
$id = (string)$photo['id'];
// Get lat and lon from points table.
$select->execute(array('timestamp' => $photo['timestamp']));
$row = $select->fetch();
$this->photos[$id]['lat'] = $row['lat'];
$this->photos[$id]['lon'] = $row['lon'];
$this->photos[$id]['elevation'] = $row['elevation'];
}

FLICKR API
$flickrMethod = 'flickr.photos.getInfo';
$apiUrl = "http://api.flickr.com/services/rest/?
method={$flickrMethod}&api_key={$this->apiKey}&photo_id={$id}";
$xml = simplexml_load_file($apiUrl);
$title = (string)$xml->photo->title;
$desc = (string)$xml->photo->description;

Google Maps OpenStreetMaps

5. Challenges
Stykkishólmur

CLUSTERS

PERFORMANCE
20,000 points loaded on a
single map is very slow
You don’t need a# points
for every view
Mature solutions exist
–http://tr.im/polyline

6. Storytelling
Reykjavík

7. Future
Tjörnin

TRAILS
GPX Tracking

GEOLOCATION API
http://mozi#a.com/en-US/firefox/geolocation/
http://dev.w3.org/geo/api/spec-source.html

Click here

FEEDBACK?
Fo#ow me on Twitter
– @shiflett
Comment on my blog
– shiflett.org
Email me
– chris@shiflett.org

Thanks for listening!
Chris Shiflett — @shiflett — shiflett.org