Book Image

OpenStreetMap

Book Image

OpenStreetMap

Overview of this book

Imagine being able to create accurate maps that look how you want them to, and use them on the Web or in print, for free. OpenStreetMap allows exactly that, with no restrictions on how or where you use your maps. OpenStreetMap is perfect for businesses that want to include maps on their website or in publications without paying high fees. With this book in hand you have the power to make, alter, and use this geographical data in a collaborative way from anywhere on the Earth.OpenStreetMap was started because most maps you think of as free actually have legal or technical restrictions on their use, holding back people from using them in creative, productive, or unexpected ways. This book will allow you to take control of your own maps and use them smoothly. This book introduces the reader to the OpenStreetMap project and shows you how to participate in the project, and make use of the data it provides. No prior knowledge of the project is assumed, and technical details are kept to a minimum.In this book, you'll learn how easy it is to add your neighborhood to OpenStreetMap using inexpensive GPS equipment, or even no GPS at all. You'll find out how to communicate with other mappers working in the same area, and where to find more information about how to map the world around you.Once you have your area mapped, you'll learn how to turn this information into maps, whether for use in print or online, large or small, and with the details you want shown. The book describes several rendering methods, each suited to different types of map, and takes you through a tutorial on each one.
Table of Contents (17 chapters)
OpenStreetMap
Credits
About the Author
About the Reviewers
Preface
4
How OpenStreetMap Records Geographical Features
Index

Reading the OpenStreetMap API from Osmosis


So far we've only dealt with data in OpenStreetMap XML files, but Osmosis can handle other sources of data, including databases and the OpenStreetMap API itself. Note that this is not the same as reading and writing to a database in API format, which we'll cover later.

Osmosis only supports the map call of the API to download data. We can get the data of Compton—the village we mapped in earlier chapters—and save it to a file using the read API task, as follows:

osmosis --read-api left="-0.64" bottom="51.21" right="-0.615" top="51.22" --write-xml file="compton.osm"

We supply the bounding box we want to download as four parameters to the read API task.

However, remember that the main API only allows you to download a limited area, so if you need a large area, this method won't work. Fortunately, you can also get Osmosis to retrieve data from XAPI by supplying its URL as another parameter. If we wanted to retrieve data of Iceland from XAPI within Osmosis...