Thuban ist ein interaktiver Geodaten-Betrachter. Die Entwicklung wurde seinerzeit gestartet, da es zu dieser Zeit keinen einfachen interkativen Betrachter für Geo-Daten als Freie Software gab. Thuban ist im wesentlichen in der Programmiersprache Python implementiert und nutzt die wxWidgets (ehemals: wxWindows) Bibliothek die es erlaubt Thuban auf verschiedenen Plattformen laufen zu lassen, darunter GNU/Linux und Windows.
Geodatenbetrachter sind wichtige Werkzeuge die es gestatten, einen visuelle Eindruck des räumlichen (gegenseiten) Bezuges von Informationen zu bekommen die ansonsten anhand der reinen Daten nicht leicht ersichtlich sind. Thuban erlaubt dem Benutzer, Sitzungen zu erzeugen, die geografische Daten darstellen. Diese können dann erforscht werden indem er durch sie sie navigieren und die Art der Darstellung ändern kann. Die Ergebnisse können gespeichert oder gedruckt werden.
Thuban strukturiert eine Sitzung hierarchisch. Eine Sitzung besteht aus Ebenen. Jede Ebene rerpäsentiert einen bestimmten Datensatz. Beispielsweise eine Ebene für Strassen und eine weitere für Gebäude. Die Ebenen können sowohl Vektor-Daten beschreiben als auch Raster-Daten.
Thuban is actively supported under Debian Testing (sarge), RedHat 7.2, and Windows 2000. Thuban depends on the following packages. These packages can also be found on the Thuban Download site .
Required:
Python 2.2.1 (http://www.python.org)
wxWindows 2.4 (http://www.wxwindows.org)
wxPython 2.4 (http://www.wxpython.org)
proj 4.4.5 Projection Library (http://www.remotesensing.org/proj/)
SQLite 2.8.3 http://www.hwaci.com/sw/sqlite/)
PySQLite 0.4.3 (http://pysqlite.sourceforge.net)
Optional:
GDAL 1.1.8 (http://www.remotesensing.org/gdal/)
psycopg 1.0.8 (http://initd.org/software/psycopg)
Along with the source codes, the download page also offers full installation packages for Debian, Windows and RPM-based systems (Mandrake, RedHat, SuSE, etc).
The most wide-spread RPM-based GNU/Linux Systems are RedHat, Mandrake and SuSE. The documentation of these distributions should contain information about how to install third-party RPM packages. Nonetheless, a short summary is provided here.
RPM packages can be installed applying several tools. The most basic one is the command line program "rpm". The hardware architecture is identified in the name of RPM packages, eg. 'i386' for most Intel/AMD architectures. If you have a different hardware architecture, where no binary RPM packages are provided, you must rebuild binary packages from the RPM source packages first (see below). Typical rpm commands look like:
rpm --install Thuban-0.9.0-1.i386.rpmDepending on what you already have installed on your system, you are informed that some packages are required, but not installed. You need to install them first. Either they are provided by your GNU/Linux distributor or available somewhere on the Internet. The more essential and special ones are provided together with the Thuban package.
For rpm exist some graphical user interfaces, notably kpackage, GnoRPM and xrpm.
Make yourself familiar with one of the tools and apply it to install the packages. Note, that you need to be administrator (root) for the system to do that.
This section describes howto build RPM install-packages from RPM source-packages. This adapts and optimizes an install-package specifically to your system. This is especially helpful to resolve version conflicts of dependent packages. Furthermore, install-packages for other platforms (e.g. PowerPC) can be created.
Note: rpm must be at least version 4. Execute rpm --version to find out about the version.
You need to do the following preparations to be able to build the packages as a regular user. You should now perform the package buling as root since this might cause damage to your system.
Create RPM directory structure: Choose a directory (e.g. $HOME/myrpm) and create the subdirectories BUILD, RPM, SOURCES, SPECS and SRPMS. A possible command sequence for this is:
mkdir $HOME/freegisrpm cd $HOME/freegisrpm mkdir BUILD RPMS SOURCES SPECS SRPMS
Set environment variable RPM_DIR:
export RPM_DIR=$HOME/freegisrpm
Create $HOME/.rpmmacros: This file sets general preferences and some specific settings for signing packages. If you don't have a GnuPG-key, you can skip the signature settings i.e. drop the last 4 lines. A signature becomes important when you want to give away packages to third parties.
%packager Name Lastname <Name.Lastname@mydomain.example> %_topdir /home/mylogin/myrpm %_signature gpg %_gpg_name Name Lastname %_pgp_path ~/.gnupg %_pgpbin /usr/bin/gpg
Create install-package: Go to the directory with the spec-files and rebuild the package:
cd $HOME/mypm/SPECS rpm -bb thuban.specNext, you will find the newly created package in $HOME/myrpm/RPMS/i386. If you build the package for another architecture than i386, then the name of the directory has a corresponding name.
For documentation of RPM, either type man rpm or rpm --help. This will provide you with information on the various command line options of RPM. For more information see the homepage of RPM.
A common installation package of Thuban for Win32 systems is available from the Thuban website download section. This installation package is configured for displaying file based vector data (Shapefiles). For the display of raster data or the connection to spatial databases additional steps are needed.
The required Python packages are listed and linked on the download page as well. If you don't have Python installed already, download the packages for Python, wxPython for Python and the SQLite Python Libraries as well as the Thuban package. Install all four packages in the order: Python, wxPython, SQLite, Thuban. Follow the installation instructions provided by the seperate setups. The Thuban installation package will add an entry in the menu folder you configured.
Enabling the raster data features of Thuban is straight forward. For the examples we assume that Thuban has been installed under C:\Thuban:
Download the zip-archive gdal-win2k.
Extract the archive (e.g. with WiZ (InfoZip)) into the C:\Thuban\Lib directory of your Thuban installation.
Extent the PYTHONPATH
environment variable (in your Windows Control Panel)
to make the new libraries available for Thuban.
%PYTHONPATH%;C:\Thuban\Lib\gdal;C:\Thuban\Lib\gdal\pymod
Extent also the PATH
environment variable accordingly:
%PATH%;C:\Thuban\Lib\gdal
To access PostgreSQL/PostGIS spatial databases with Thuban you have to install the PsycoPG package for Windows:
Download the zip-archive win-psycopg22.zip.
Extract the zip-archive into a directory either already
in your PYTHONPATH
or extent your
PYTHONPATH
variable to the directory
you have extracted the archive to.