GRASS 6 Tutorial

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The Free Software/Open Source GIS GRASS 6 is fully operational and stable version for production use. This tutorial tries to give you a hand to familiarize yourself with the improved functionality, especially in the vector engine and attribute management. For further reading, see the references below.

Disclaimer: In case the examples described here do not work properly, you are kindly invited to send us further examples and/or code bugfixes/enhancements. Enjoy the WIKI!

This tutorial is intended for GRASS users who want to migrate from a previous release to the new GRASS Version. If you are a beginner, please also consider additional books or tutorials.

NOTE: This tutorial here still awaits the merge of the previous GRASS 5.7 tutorial.

Introduction

New GRASS development has made major improvements to the vector architecture. The most significant change includes a new 2- and 3-dimensional vector library that manages vector attributes in standard database management systems (DBMS). This system provides the power of true relational databases for vector attribute management while preserving the flexibility of traditional GRASS topological tools. GRASS now also incorporates true 3-dimensional voxels in the NVIZ visualization environment as well as numerous enhancements to virtually every tool in the GRASS library.

Getting started in general

Getting started - how to migrate to the new GRASS version

Raster data management

  • The raster management works as it did in previous GRASS versions.
Tutorials and books written for GRASS 4 and 5 should for the most part still work.

Vector data management

Overview

The native GRASS vector format provides:

  • Vector topology
  • m:n mapping of geometry features to attributes
  • Vector layers
  • OGC Simple Features <-> Topological Vector Conversion
  • Database Management system (DBMS)
  • SQLite, PostgreSQL + PostGIS, MySQL, ODBC (, DBF)

Vector Geometry Types

  • Point
  • Centroid
  • Line
  • Boundary
  • Area (Boundaries + Centroid)
  • Face (3D Area)
  • [Kernel (3D Centroid)]
  • [Volumes (Faces + Kernel)]

All types are true 3D: x,y,z

Import/Export of Vector data

v.in.* and v.out.* v.out.ogr always exports the entire vector map

OGR supported formats is in excess of 50

Introductory information on vector data processing is available from the help manual.

Grass Six Tutorial Default Settings

      -  Default settings for vector geometry;
         for vector attributes; for db.* modules

Grass Six Tutorial Geometry Management

http://grass.osgeo.org/grass57/tutorial/geom_storage.html

       -  General notes on Geometry 
         management; Managing the default settings; 
         GRASS vector architecture; Geometry stored in native format;
         Geometry stored in SHAPE file; 
         Import/export of vector data Geometry;
         Generating vector geometry from various sources

Grass Six Tutorial Attribute Management

http://grass.osgeo.org/grass57/tutorial/attrib_storage.html

       - General notes on Attribute 
         management; Managing the default settings; Examples;
         Database Schema

Usage examples

There await porting from the GRASS 5.7 tutorial

Basic usage examples

http://grass.osgeo.org/grass57/tutorial/ex_basic.html

Complex usage examples

http://grass.osgeo.org/grass57/tutorial/ex_complex.html

Vector network analysis examples

Vector overlay/clipping examples

http://grass.osgeo.org/grass57/tutorial/vectoroverlay.html

Examples from US National Atlas

http://grass.osgeo.org/grass57/tutorial/usa_demo.html

FAQ (Frequently Asked Questions)

Troubleshooting

http://grass.osgeo.org/grass57/tutorial/troubleshooting.html

  • Grass Six Tutorial Troubleshooting

Links of interest

Further reading

GRASS and R kriging interpolation

Mini How to interpolate using kriging with GRASS and R

How to interpolate point value using kriging method with R and GRASS 6

References