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
About the Authors
About the Reviewers

Joining layer data

We often get data in different formats and information spread over multiple files. Therefore, one important skill to know is how to join attribute data from different layers. Joining data is a way to combine data from multiple tables based on common values, such as IDs or categories.

This exercise shows you how to use the join functionality in Layer Properties to join geographic census tract data to tabular population data and how to save the results to a new file.

Getting ready

To follow this exercise, load the census tracts in census_wake2000.shp using Add Vector Layer (you can also drag and drop the shapefile from the file browser to QGIS) and population data in census_wake2000_pop.csv using Add Delimited Text Layer.


You can also load the .csv text file using Add Vector Layer, but this will load all data as text columns because the .csv file does not come with a .csvt file to specify data types. Instead, the Add Delimited Text Layer tool will scan the data and determine...