Getting the Most Out of QGIS and GRASS Integration - Desktop GIS: Mapping the Planet with Open Source Tools - page 197

Chapter 12

Getting the Most Out of

QGIS and GRASS Integration

We have mentioned the QGIS-GRASS integration in a number of places
so far. In this chapter, you will see how QGIS can serve as a front end
for viewing and editing GRASS data, as well as for performing analysis
and data conversion. We're venturing into some powerful territory here,
allowing you to harness the geoprocessing power of GRASS.

QGIS supports GRASS through the use of a plugin. The plugin pro-
vides access to GRASS data and functions and is distributed with all
official QGIS packages. Actually, it consists of a data provider to bridge
between a GRASS map layer and the QGIS map canvas and a plugin to
provide the user interface. Well, enough of the boring details; let's get
started by loading up the GRASS plugin and seeing how it all works.

To review, when you initially start QGIS, there are no plugins loaded.
To load a plugin, you use the Plugin Manager, found in the Plugins
menu. The Plugin Manager provides a list of all the available plugins
and whether they are currently loaded (indicated by a checkbox next to
their names). To load the GRASS plugin, click the checkbox next to its
name, and click the OK button. This loads the GRASS plugin, adds a
GRASS menu to the Plugins menu, and adds a new toolbar to the GUI.
For a review of plugins in QGIS, see Section D.4 , Plugins, on page 339 .

If you have followed along with some of the previous GRASS examples,
you probably recall how to load the GRASS plugin in QGIS and create
a location. If not, refer to Section C.1 , Location, Location, Location, on
page 296 for a refresher. You might also want to take a look at Sec-
tion C.2 , Importing with QGIS, on page 313 for information on how to