Postcode widget – Part 2


August 16, 2008

The Easypeasy Database

Today I’ve been testing the Easypeasy database for my widget project.

I began by installing the data to MySQL. Very easy to do as the downloadable zip comes with a file you can import directly into MyAdmin.

With the database installed I used two scripts to look at the data in more detail. Firstly, one to establish the initial database connecion – it’s an idea to keep this file separate so you only have to write it once. Then, a second script that builds a form and processes the results.

Once I started to plot my results it quickly became apparent that although Latitude and Longitude is returned for each entry, the numbers are all rounded up. This puts W10 and SE13 on the same spot, so there’s still a bit of work to do to figure out how to the x and y fields effect the results.

Here’s the code I wrote for the form:

<form action="<?php echo $_SERVER['PHP_SELF']?>" method="post">
Input Post Code:</br>&ltinput type="text" name="code" size="30">
<input type="submit" name="submit" value="submit">
</form>

<?php

//Connect to the database
include 'connect.php';

//If the form has been submitted then process the form
if (isset($_POST['code'])) {

//Grab the Postcode from the form
$postcode = $_POST['code'];

//Convert the Postcode to all uppercase
$postcode = strtoupper($postcode);

//Break the Postcode into two
list($outcode, $partTwo) = split(' ', $postcode);

//Pull out the relevant fields from our database
$query = "SELECT latitude,longitude FROM hwz_postcodes WHERE
outcode = '$outcode'";
$result = mysql_query($query) or die('Query failed: '.mysql_error());
$line = mysql_fetch_array($result, MYSQL_ASSOC);

//Print Results
print $postcode.' : ';
print $line['latitude'].','.$line['longitude'];

//We've finished with the database, so close the connection
mysql_close($conn);
}

?>

Google Badge Map


August 2, 2008

Click here to see a working version

Here’s an experimental Google map made using some excellent software from UCL Centre for Advanced Spacial Analaysis (Casa). The application slices up a large digital image – the one used here is 8000 x 8000px 30mb into a 256 x 256 pixel tiles (you might have noticed the how the map image builds up from these unit blocks).

The tiles correspond to the magnification of the map. At the lowest level the entire image is contained within a single 256 pixel square repeated left and right – this is the maps initial state. As you zoom in the tile samples are closer to the original image resolution.

The plan for the map is to lay a data layer on top of the map corresponding to each individual badge. This will hook up to the eBay API so when it comes time to sell the badges we can see a live data feed.

References:

Casa
http://www.casa.ucl.ac.uk/software/googlemapimagecutter.asp

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Postcode Widget – Part 1


July 31, 2008

Background

After playing around with Google maps for a few days it became apparent that having a list of UK postcodes plus the corresponding latitude and longitude to each would come in very handy for a lot of people. If you had such a thing you could build loads of exciting applications, from route planning to food mile calculators.

The problem is that here in the UK the list doesn’t exist in the public domain. It’s available from the Post Office, but it’ll cost you, making it effectively useless for most small groups and enterprises.

What’s currently available from Easypeasy is the first half of the code. With this you can break the UK into about 3,000 separate parts, narrowing a location to within a few kilometres.

Project Brief

There appear to be two groups pushing the Postcode into the public domain, Free the Postcode and New Popular Edition Maps.

What I’d like to do is build a widget that people can put on their website that makes it easy for the general public to enter their Postcode, and help build the free database. Currently you are required to specifically visit either of the two website and with Free the Postcode know by heart your latitude and longitude.

Using the Google Map API combined with the first half of the postcode the widget would pull up a map of your local area, from here it’s easy to stick a pin where you live or work, and then after (an email?) authentication your postcode is added to the database.

References

Free the Postcode: www.freethepostcode.org

New Popular Edition Maps: www.npemap.org.uk

Postcode Schema: www.govtalk.gov.uk/gdsc/html/frames/PostCode.htm

Easypeasy: www.easypeasy.com/guides/article.php?article=64