Book Image

QGIS 2 Cookbook

By : Alex Mandel, Víctor Olaya Ferrero, Anita Graser, Alexander Bruy
Book Image

QGIS 2 Cookbook

By: Alex Mandel, Víctor Olaya Ferrero, Anita Graser, Alexander Bruy

Overview of this book

QGIS is a user-friendly, cross-platform desktop geographic information system used to make maps and analyze spatial data. QGIS allows users to understand, question, interpret, and visualize spatial data in many ways that reveal relationships, patterns, and trends in the form of maps. This book is a collection of simple to advanced techniques that are needed in everyday geospatial work, and shows how to accomplish them with QGIS. You will begin by understanding the different types of data management techniques, as well as how data exploration works. You will then learn how to perform classic vector and raster analysis with QGIS, apart from creating time-based visualizations. Finally, you will learn how to create interactive and visually appealing maps with custom cartography. By the end of this book, you will have all the necessary knowledge to handle spatial data management, exploration, and visualization tasks in QGIS.
Table of Contents (19 chapters)
QGIS 2 Cookbook
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Estimating density heatmaps


Whether they are animal sightings, accident locations, or general points of interest, many point datasets can be interpreted more easily by visualizing the point density using a heatmap. In this recipe, we will estimate the density of POIs in Wake county to find areas with a high density.

Getting ready

Load the poi_names_wake.shp POI dataset from our sample data. Make sure that the Heatmap plugin, which comes with QGIS by default, is enabled in Plugin Manager.

How to do it…

Using the following steps, we can calculate the POI heatmap:

  1. Start the Heatmap plugin from the Raster menu.

  2. Make sure that poi_names_wake is selected as Input point layer.

  3. Select a location and filename for Output raster. You don't need to specify the file extension because this will be added automatically, based on the selected Output format. GeoTIFF is usually the first choice.

  4. Select a search Radius of 1000 meters.

  5. The Add generated file to map option should be activated by default. Click on OK to...