QGIS By Example电子书

QGIS By Example

Table of Contents

QGIS By Example

Credits

About the Authors

About the Reviewers

www.PacktPub.com

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Why subscribe?

Free access for Packt account holders

Preface

What this book covers

What you need for this book

Who this book is for

Conventions

Reader feedback

Customer support

Downloading the example code

Downloading the color images of this book

Errata

Piracy

Questions

1. Handling Your Data

Installing QGIS

GUI elements and customization

Extending functionality through plugins

Managing plugins

Loading data into QGIS

Loading shapefiles

Loading rasters

Loading data from the Personal GeoDatabase

Importing CSV files

Loading GPS data

Getting OpenStreetMap data

Dealing with projections

Data source projection

Project projection

Loading layers to a spatial database

Summary

2. Visualizing and Styling the Data

Loading layers from the spatial database

Grouping and reordering layers

Developing your own styles

Developing styles for vector layers

Styling a layer with the Single Symbol renderer

Styling a layer with the Categorized renderer

Styling a layer with the Graduated renderer

Styling a layer with the Rule-based renderer

Styling a layer with the Point displacement renderer

Styling a layer with the Inverted polygons renderer

Styling a layer with the Heatmap renderer

Layer rendering

Developing styles for raster layers

Adding labels

Labeling a point layer

Labeling a line layer

Labeling a polygon layer

Advanced labeling

Managing styles

Using several styles for the same layer

Adding base maps

The OpenLayers plugin

Adding WMS/WMTS layers

Adding TMS layers

Summary

3. Presenting Data on a Print Map

Print composer

The initial setup – page format and other essentials

Adding and customizing a map

Adding and customizing a legend

Other map items

Scale bar

North arrow

Other items

Working with multiple maps and overviews

Combining several maps within a single print composer

Working with map overviews

Creating atlases

Managing print composers

Summary

4. Publishing the Map Online

Registering for the QGIS Cloud service

The QGIS Cloud plugin

Creating a database

Publishing the map

General settings

WMS settings

WFS settings

Viewing your map in QGIS and a browser

Working with a map from a browser

Working with a map in QGIS

Deleting unused maps

Deleting layers with DB Manager

Deleting databases from the QGIS Cloud plugin

Deleting maps from the web interface

Summary

5. Answering Questions with Density Analysis

Density analysis and heatmaps

Creating heat maps with the Heatmap plugin

Detecting the "hottest" regions

Looking for distribution patterns with contour lines

Mapping density with a hexagonal grid

Creating a hexagonal grid

Counting points in grid cells

Removing redundant data

Summary

6. Answering Questions with Visibility Analysis

The basics of visibility analysis

Step 1 – converting a buildings' vector layer to raster

Step 2 – combining the DEM and buildings layers

Step 3 – defining observation points

Creating an empty vector layer

Populating a layer with points

Providing points with height values

Step 4 – creating viewshed coverages

Step 5 – finding scenic points

Step 6 – styling the results in 3D

Working on the general settings of a 3D scene

Adjusting 3D visualization of the observation points

Adjusting 3D visualization of building footprints

Summary

7. Answering Questions with Suitability Analysis

Basics of suitability analysis

Step 1 – define the goal and objectives of our analysis

Step 2 – analyze the available data and define its relevance

Step 3 – define the criteria of analysis

Step 4 – Analyze and prepare the data

Rasterizing and ranking categorized vector layers

Ranking density rasters

Generating and ranking proximity rasters

Step 5 – overlay the data and interpret the results

Summary

8. Automating Analysis with Processing Models

The QGIS Processing framework

Graphical Modeler

Adding inputs

Implementing the workflow

Filling model metadata and saving

Editing models

Sharing models

Summary

9. Automating Analysis with Processing Scripts

Python scripts in Processing

Listing the available algorithms

Getting information about an algorithm

Executing the algorithm and loading the results

Defining inputs and outputs

Implementing the algorithm

Writing help and saving

Sharing scripts

Summary

10. Developing a Python Plugin – Select by Radius

QGIS plugins

Creating the plugin's skeleton

Designing the plugin's GUI

Designing the About dialog

Designing the main plugin dialog

Using Designer UI files in the plugin

Adding the About dialog to the plugin

Adding the main plugin dialog

Implementing feature selection

Adding translations

Preparing the plugin for publishing

Summary

Index