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About Lion1906

This page provides information about Lion1906: how it works, its information sources, its origins, and what it will become next...

- How it works
- The database
- Geo-proximity
- Travel itinerary: no way!
- About Lion1906
- Acknowledgements

How it works

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Below is a rough explanation of how the website works.

The website is hosted on a computer connected to the Internet 24 hours a day 7 days a week. This computer is called a server. Lion1906 is nothing but a set of simple text pages but some pages are special in that they contain programming code.
The interesting thing is that because the server where the pages are hosted is a computer, one can ask the server to make calculations. Different programs allow you to do different things. This is how the result of any specific query is calculated and then displayed on the result page. All search engines work the same way: after you enter a keyword, the program queries a database and then displays the result.
The programming language used on Lion1906 is 'PHP'. To perform the calculations, PHP is associated with a 'MySQL' database that contains the town names, longitudes, latitudes, postal codes, INSEE codes, etc.
For example, when you're looking for a particular town, the PHP program asks MySQL to find the inputted entry among all locations in France, and then returns the information found such as its longitude and latitude. Then, the distance to another town can be computed by applying the great-circle formula.

To display a point representing the position of the searched town on the map of France or inside a departement, we use its longitude and latitude: An empty map serves as the basis overlay, and a PHP graphical extension called 'GD' then adds the required pixels to the image. For exact positioning, a scale and origin are defined and serve as a basis for a given map of x pixels. The longitude and latitude coordinates are converted into pixel values to determine the position of the location on the map. This is how the user obtains a little dot on the map of France representing the position of the searched location.

The database

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To perform calculations, Lion1906 requires a database. Different databases can be found on the internet using any standard search engine. There are many files available so please, do not ask me for the database. The database I'm using on lion1906 is the result of several files merged together. Each file contains either Lambert coordinates, postal codes, INSEE codes, altitudes, population based on the 1990 and 1999 censuses, or density. To output the most comprehensive results about any given location, multiple queries are run across all the files listed above.


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Lion1906 allows you to perform geo-proximity searches ie. the program can list the locations around any given town within a radius of xx km. To achieve this, the technique used is based on the great-circle formula. The database is queried producing a list of near-by locations based on 2 intervals ie. maximum and minimum difference (longitude and latitude). For each location found, great-circle distances are calculated and the results are then sorted and displayed in ascending order.

Travel itinerary: no way!

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Will I ever produce travel itineraries and super detailed maps?
The anwser is 'No', I think. First, I don't want Lion1906 to go this way and it would take me way too much time to develop such programs (plus I wouldn't even know where to start!). Also, I would need road information for the whole territory, which would be anything but easy given the small quantity of free information available out there! Last, Lion1906 does not rely on the same technology -- great technology, by the way. I would be unable to explain the technology used in detail, but those websites most probably rely on a GIS with huge databases for the maps, a unidirectional and bidirectional vector system (for one-way streets for example) together with codes for the different road types, and a route generation system based on general routes used to produce itineraries.

About Lion1906

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Lion1906 was born in September 2001. At that time, I had just been fired from a Web start-up, and all I wanted was to promote myself as a Web programmer. It all started with one page: my resume. Next, I came up with the idea of presenting my resume in a little "demo". When I was working on the design of the Europotel website, I submitted the idea of geo-locating the different hotels, camp sites and B&Bs on a map of France or departement map, and suggest near-by hotels etc. in case the ones in the searched location were fully booked or unavailable. My proposal was rejected and so I decided to keep this idea for myself and bring it to life on my own website. This is how I started working on great-circle distances, the geolocation engine, and then the geo-proximity engine.
So it all really started as a way for me to demonstrate my modest Web programming skills. Later however, some people started to show some interest and the website soon became a priority. Since then, I've developed the site further trying to improve the concept whenever time allows...


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I would like to thank the people who've linked to Lion1906 on their websites. Here are some examples:

I would also like to thank those people contributing articles to the Wikipedia project.
This is now the third version of Lion1906 and I'm still improving it whenever I can. I now have over 15,000 unique visitors a day and over 170,000 pages displayed everyday (as of end of January 2007). So, I would like to thank you all for visiting my website, sending me thankyou notes and leaving your messages in the forum and visitor's book.
I would like to thank my old friend Romain Dal for localizing the website into English.
And I also want to thank my wife and daughters for the time I spend working on the website instead of being with them. You bring me so much love and comfort.
Last, I want to thank Free for their free hosting service of

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