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<?xml version="1.0" encoding="ISO-8859-1"?> |
<?xml version="1.0" encoding="ISO-8859-1"?> |
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<!DOCTYPE book |
<!DOCTYPE book |
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PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" |
PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" |
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"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> |
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" |
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[<!ENTITY imgscale "70">]> |
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<!-- $Revision$ --> |
<!-- $Revision$ --> |
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<book> |
<book> |
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<bookinfo> |
<bookinfo> |
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<author> |
<author> |
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<firstname>Jan-Oliver</firstname><surname>Wagner</surname> |
<firstname>Jan-Oliver</firstname><surname>Wagner</surname> |
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</author> |
</author> |
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<author> |
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<firstname>Frank</firstname><surname>Koormann</surname> |
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</author> |
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<copyright> |
<copyright> |
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<year>2003</year> |
<year>2003</year> |
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<holder>Intevation GmbH</holder> |
<holder>Intevation GmbH</holder> |
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|
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<chapter><title>Introduction</title> |
<chapter><title>Introduction</title> |
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<para> |
<para> |
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Thuban is a Free Software Geographic Information Systems (GIS) viewer. |
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It is being developed because there is currently no simple interactive |
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viewer for geographic information available as Free Software. Thuban is |
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written in Python and C++ and uses the wxWindows library allowing it to |
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run on many different platforms, including GNU/Linux and Windows. |
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</para> |
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<para> |
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GIS viewers are a necessary tool as they allow one to get a visual |
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impression of the positional relationship of the information that may not |
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be apparent from simple inspection of the data values themselves. |
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Thuban allows the user to create a session that displays |
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geographic data and then explore that data through navigation and |
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manipulation of how it is drawn. The results can then be saved or printed. |
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</para> |
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<para> |
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Thuban arranges a session in a hierarchy. A session contains a map which |
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consists of layers. Each layer represents one kind of data set. For |
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instance, there may be a layer for roads and another layer for buildings. |
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These layers can either be vector shapes or images. |
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</para> |
</para> |
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|
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<section><title>Installation</title> |
<section><title>Installation</title> |
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<para> |
<para> |
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</para> |
Thuban is actively supported under Debian Testing (sarge), RedHat 7.2, |
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and Windows 2000. The following list of files that Thuban requires |
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can be found on the |
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<ulink url="http://thuban.intevation.org/download.html"> |
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Thuban Download site |
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</ulink>. |
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<variablelist> |
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<varlistentry> |
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<term>Debian Testing (sarge)</term> |
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<listitem> |
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<itemizedlist> |
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<listitem><para>Thuban-0.8.1-1-debian.i386.rpm</para></listitem> |
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<listitem><para>GTK 1.2.3</para></listitem> |
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<listitem><para>Python 2.2.1</para></listitem> |
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<listitem><para>Python 2.2 XML Base Tools</para></listitem> |
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<listitem><para>wxWindows 2.4</para></listitem> |
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<listitem><para>wxWindows 2.4 Python Bindings</para></listitem> |
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<listitem><para>proj 4.4.5 Projection Library</para></listitem> |
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<listitem><para>SQLite Python Bindings 0.4.3</para></listitem> |
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<listitem><para>GDAL 1.1.8</para></listitem> |
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</itemizedlist> |
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</listitem> |
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</varlistentry> |
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<varlistentry> |
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<term>RedHat 7.2</term> |
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<listitem> |
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<itemizedlist> |
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<listitem><para>Thuban-0.8.1-1.i386.rpm</para></listitem> |
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<listitem><para>Python 2.2.1</para></listitem> |
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<listitem><para>wxPython 2.4 for Python 2.2 with wxGTK</para></listitem> |
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<listitem><para>proj 4.4.5 Projection Library</para></listitem> |
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<listitem><para>SQLite 2.8.3</para></listitem> |
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<listitem><para>PySQLite 0.4.3</para></listitem> |
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<listitem><para>GDAL 1.1.8</para></listitem> |
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</itemizedlist> |
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</listitem> |
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</varlistentry> |
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<varlistentry> |
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<term>Windows 2000</term> |
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<listitem> |
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<itemizedlist> |
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<listitem><para>Thuban-0.8.1-0.exe</para></listitem> |
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<listitem><para>Python 2.2.1</para></listitem> |
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<listitem><para>wxWindows 2.4 for Python 2.2</para></listitem> |
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<listitem><para>SQLite Python Libraries</para></listitem> |
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<listitem><para>GDAL for Thuban</para></listitem> |
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</itemizedlist> |
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</listitem> |
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</varlistentry> |
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</variablelist> |
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</para> |
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</section> |
</section> |
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|
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<section><title>The main window</title> |
<section><title>The Main Window</title> |
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<para> |
<para> |
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map, legend window (dockable), Statusbat, toolbar, |
<figure> |
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other general stuff |
<title>The Main Window</title> |
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</para> |
<mediaobject> |
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<imageobject> <imagedata fileref="../images/1_2_mainwindow.png" format="PNG" scale="&imgscale;"/> </imageobject> |
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<imageobject> <imagedata fileref="./images/1_2_mainwindow.ps" format="EPS" scale="&imgscale;"/> </imageobject> |
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</mediaobject> |
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</figure> |
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</para> |
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|
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<para> |
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The map window shows the current state of the map and is where |
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the user can interact with the map using the tools. |
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</para> |
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|
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<para> |
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The legend on the left displays a list of the current layers and |
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any visible classification groups. In the example, each shape layer |
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has a default classification which specifies how the shapes in each |
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layer are drawn. Layers that are higher in the list appear |
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``closer'' to the user. The legend can be closed by clicking on the |
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small X in the upper right-hand region of the legend. |
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To open it again, use |
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<menuchoice> |
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<guimenu>Map</guimenu> |
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<guimenuitem>Legend</guimenuitem> |
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</menuchoice>. |
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The legend is also dockable, which means that it can be detached |
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from the main window by clicking on the small button next to the |
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close button. It can be attached by clicking the same button |
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again. |
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</para> |
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<para> |
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The status bar displays different information depending on the |
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current context. If the user is selecting an item from the menu |
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then the status bar will display a short help message indicating |
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what each menu item is for. If the user has a tool selected then |
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the position of the cursor on the map is displayed. |
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</para> |
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<para> |
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The tool bar provides quick access to the commonly needed tools. |
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By hovering over each button the user can see a short messages |
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describing what the tool does. The tools provided are Zoom In, Zoom |
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Out, Pan, Full Extent, Full Layer Extent, Full Shape Extent, Identify, |
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and Label. Each of the tools will be explained in further detail later |
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in the manual. |
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</para> |
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</section> |
</section> |
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|
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</chapter> |
</chapter> |
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|
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<chapter><title>Session Management</title> |
<chapter><title>Session Management</title> |
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<para> |
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</para> |
|
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|
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<section><title>Starting a new session</title> |
<section><title>Starting a New Session</title> |
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<para> |
<para> |
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A new session can be started from |
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<menuchoice> |
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<guimenu>File</guimenu> |
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<guimenuitem>New Session</guimenuitem> |
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</menuchoice>. |
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If a session is already loaded and has been modified without |
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being saved a prompt will ask if the current session should |
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be saved. A new session consists of an empty map with no |
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layers and no tables. |
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</para> |
</para> |
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</section> |
</section> |
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|
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<section><title>Opening a session</title> |
<section><title>Opening a Session</title> |
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<para> |
<para> |
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A session can be opened from |
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<menuchoice> |
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<guimenu>File</guimenu> |
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<guimenuitem>Open Session</guimenuitem> |
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</menuchoice>. A dialog box will open allowing the user to browse |
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for a Thuban Session file. Thuban session files end with |
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<varname>.thuban</varname>. Selecting a file a clicking |
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<guibutton>OK</guibutton> will load the session into Thuban. |
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|
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If a session is already loaded and has been modified without |
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being saved a prompt will ask if the current session should |
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be saved. |
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</para> |
</para> |
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</section> |
</section> |
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|
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<section><title>Saving a session</title> |
<section><title>Saving a Session</title> |
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<para> |
<para> |
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A session can be saved from |
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<menuchoice> |
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<guimenu>File</guimenu> |
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<guimenuitem>Save Session</guimenuitem> |
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</menuchoice>. A dialog box will open allowing the user to browse |
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the file system and select a place to save the session. Thuban |
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sessions should be saved under a name ending in |
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<varname>.thuban</varname>. If the file already exists the user |
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will be prompted to save under a different name or overwrite the |
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existing file. |
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</para> |
</para> |
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</section> |
</section> |
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|
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<section><title>The session info-tree</title> |
<section><title>The Session Info-Tree</title> |
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<para> |
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<figure> |
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<title>Session Info Tree</title> |
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<mediaobject> |
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<imageobject><imagedata fileref="../images/2_4_session_tree.png" format="PNG" scale="&imgscale;"/></imageobject> |
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<imageobject><imagedata fileref="./images/2_4_session_tree.eps" format="EPS" scale="&imgscale;"/></imageobject> |
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</mediaobject> |
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</figure> |
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</para> |
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<para> |
<para> |
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(primarily for developers) |
The session info-tree is primarily intended for developers working |
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with Thuban. It displays many of the internal values for the session, |
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map, and layers. It can be opened from |
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<menuchoice> |
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<guimenu>File</guimenu> |
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<guimenuitem>Session Tree</guimenuitem> |
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</menuchoice>. |
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</para> |
</para> |
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</section> |
</section> |
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</chapter> |
</chapter> |
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|
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<chapter><title>Map Management</title> |
<chapter><title>Map Management</title> |
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<para> |
<para> |
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The map consists of a number of layers where each layer represents a |
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different type of data set. By interacting with the map the user can |
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visually explore the data. |
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</para> |
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<para> |
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The map can have a name that will appear in the Thuban title bar. |
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The map name can be changed using |
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<menuchoice> |
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<guimenu>Map</guimenu> |
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<guimenuitem>Rename</guimenuitem> |
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</menuchoice>. |
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</para> |
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<para> |
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<inlinemediaobject> |
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<imageobject> |
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<imagedata fileref="../images/3_rename_map.png" format="PNG" scale="&imgscale;"/> |
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</imageobject> |
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<imageobject> |
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<imagedata fileref="./images/3_rename_map.eps" format="EPS" scale="&imgscale;"/> |
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</imageobject> |
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<textobject> <phrase>Rename Map</phrase> </textobject> |
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</inlinemediaobject> |
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</para> |
</para> |
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|
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<section><title>Adding and removing layers</title> |
<section><title>Adding and Removing Layers</title> |
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<para> |
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There are two types of layers that can be added to a map: shape layers |
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and image layers. Shape layers are stored in Shapefile format, a |
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standard file format for storing geographic objects. These |
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files have the extension ``.shp''. Associated with |
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the shape file is a database file which stores attributes for |
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each shape in the shape file. This file, in dBase format, |
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has the extension ``.dbf''. Both files must have the same base name. |
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For example, if there is a shape file named roads.shp there must |
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also be a file roads.dbf. |
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</para> |
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<para> |
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Shape layers can be added to the map with |
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<menuchoice> |
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<guimenu>Map</guimenu> |
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<guimenuitem>Add Layer</guimenuitem> |
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</menuchoice>. |
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Thuban will load all files with the same base name, so it doesn't |
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matter if the shape file or database file is selected. |
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</para> |
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|
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<para> |
<para> |
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Image layers can be added to the map with |
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<menuchoice> |
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<guimenu>Map</guimenu> |
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<guimenuitem>Add Image Layer</guimenuitem> |
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</menuchoice>. |
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It is important to select a valid image file that has geographic |
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data associated with it. The data can be embedded in the file itself, |
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or in another file. If geographic information cannot be found, Thuban |
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will report an error. |
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</para> |
</para> |
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</section> |
</section> |
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|
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<section><title>Navigation</title> |
<section><title>Navigation</title> |
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<para> |
<para> |
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The map can be explored by using the navigation tools available on |
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the tool bar or from the |
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<menuchoice><guimenu>Map</guimenu></menuchoice> menu. |
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</para> |
</para> |
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<itemizedlist> |
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<listitem> |
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<para> |
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The ZoomIn tool |
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<inlinemediaobject> |
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<imageobject> |
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<imagedata fileref="../images/3_2_zoomin.png" format="PNG" scale="&imgscale;"/> |
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</imageobject> |
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<imageobject> |
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<imagedata fileref="./images/3_2_zoomin.eps" format="EPS" scale="&imgscale;"/> |
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</imageobject> |
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<textobject> <phrase>ZoomIn Tool</phrase> </textobject> |
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</inlinemediaobject> |
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enlarges a region of the map. Clicking once on the map |
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will double the magnification and center the map on the point that |
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was clicked. Clicking and dragging selects a region that will be |
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enlarged to fit the window. |
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</para> |
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</listitem> |
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|
<listitem> |
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|
<para> |
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The ZoomOut tool |
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<inlinemediaobject> |
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<imageobject> |
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<imagedata fileref="../images/3_2_zoomout.png" format="PNG" scale="&imgscale;"/> |
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</imageobject> |
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<imageobject> |
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<imagedata fileref="./images/3_2_zoomout.eps" format="EPS" scale="&imgscale;"/> |
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</imageobject> |
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<textobject> <phrase>ZoomOut Tool</phrase> </textobject> |
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</inlinemediaobject> |
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shrinks the map so that a larger region is visible. A single click |
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reduces the magnification by a factor of two. Clicking and dragging |
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selects a box such that the current contents of the window will be |
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scaled to fit into that box. |
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</para> |
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</listitem> |
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<listitem> |
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<para> |
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The Pan tool |
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<inlinemediaobject> |
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<imageobject> |
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<imagedata fileref="../images/3_2_pan.png" format="PNG" scale="&imgscale;"/> |
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</imageobject> |
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<imageobject> |
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<imagedata fileref="./images/3_2_pan.eps" format="EPS" scale="&imgscale;"/> |
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</imageobject> |
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<textobject> <phrase>Pan Tool</phrase> </textobject> |
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</inlinemediaobject> |
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allows the user to move the map around by clicking and dragging. |
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</para> |
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</listitem> |
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<listitem> |
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|
<para> |
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The Full Extent tool |
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<inlinemediaobject> |
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<imageobject> |
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<imagedata fileref="../images/3_2_fullextent.png" format="PNG" scale="&imgscale;"/> |
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</imageobject> |
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<imageobject> |
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<imagedata fileref="./images/3_2_fullextent.eps" format="EPS" scale="&imgscale;"/> |
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</imageobject> |
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<textobject> <phrase>Full Extent Tool</phrase> </textobject> |
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</inlinemediaobject> |
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rescales the viewable region so that the entire map is visible. |
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</para> |
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</listitem> |
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<listitem> |
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|
<para> |
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The Full Layer Extent tool |
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<inlinemediaobject> |
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<imageobject> |
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<imagedata fileref="../images/3_2_fulllayerextent.png" format="PNG" scale="&imgscale;"/> |
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</imageobject> |
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<imageobject> |
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<imagedata fileref="./images/3_2_fulllayerextent.eps" format="EPS" scale="&imgscale;"/> |
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</imageobject> |
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<textobject> <phrase>Full Layer Extent Tool</phrase> </textobject> |
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</inlinemediaobject> |
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rescales the viewable region so that the currently selected |
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layer fits within the window. If no layer is selected this button |
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will be disabled. |
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</para> |
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</listitem> |
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|
<listitem> |
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|
<para> |
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|
The Full Shape Extent tool |
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<inlinemediaobject> |
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<imageobject> |
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<imagedata fileref="../images/3_2_fullshapeextent.png" format="PNG" scale="&imgscale;"/> |
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</imageobject> |
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<imageobject> |
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<imagedata fileref="./images/3_2_fullshapeextent.eps" format="EPS" scale="&imgscale;"/> |
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</imageobject> |
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<textobject> <phrase>Full Shape Extent Tool</phrase> </textobject> |
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</inlinemediaobject> |
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rescales the viewable region so that the currently selected |
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shape fits within the window. If the shape is a point, it is |
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centered and the map is zoomed all the way in. If no shape is |
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selected this button will be disabled. This feature is especially |
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helpful when identifying an object related to a selected record |
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in a tableview (see below). |
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|
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</para> |
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</listitem> |
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</itemizedlist> |
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</section> |
</section> |
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|
|
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<section><title>Object identification</title> |
<section><title>Object Identification</title> |
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<para> |
<para> |
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Objects on the map can be identified using the Identify tool |
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<inlinemediaobject> |
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<imageobject> |
405 |
|
<imagedata fileref="../images/3_3_identify.png" format="PNG" scale="&imgscale;"/> |
406 |
|
</imageobject> |
407 |
|
<imageobject> |
408 |
|
<imagedata fileref="./images/3_3_identify.eps" format="EPS" scale="&imgscale;"/> |
409 |
|
</imageobject> |
410 |
|
<textobject> <phrase>Identify Tool</phrase> </textobject> |
411 |
|
</inlinemediaobject>. |
412 |
|
Clicking on an object selects that object and opens a dialog which |
413 |
|
shows all the table attributes for that object. Any current selection |
414 |
|
is lost. Objects on the map are typically shapes and this document |
415 |
|
will often refer to objects as shapes. |
416 |
</para> |
</para> |
417 |
</section> |
</section> |
418 |
|
|
419 |
<section><title>Object labelling</title> |
<section><title>Object Labeling</title> |
420 |
<para> |
<para> |
421 |
|
Objects can be labeled using the Label tool |
422 |
|
<inlinemediaobject> |
423 |
|
<imageobject> |
424 |
|
<imagedata fileref="../images/3_3_label.png" format="PNG" scale="&imgscale;"/> |
425 |
|
</imageobject> |
426 |
|
<imageobject> |
427 |
|
<imagedata fileref="./images/3_3_label.eps" format="EPS" scale="&imgscale;"/> |
428 |
|
</imageobject> |
429 |
|
<textobject> <phrase>Label Tool</phrase> </textobject> |
430 |
|
</inlinemediaobject>. |
431 |
|
Clicking on an object selects that object and opens a dialog which |
432 |
|
displays the table attributes for that object. An attribute can |
433 |
|
be selected to be the label on the map. The label will be placed |
434 |
|
at the center of the shape. Clicking on an object that already has |
435 |
|
a label will remove the label. |
436 |
</para> |
</para> |
437 |
</section> |
</section> |
438 |
|
|
439 |
<section><title>The legend</title> |
<section><title>The Legend</title> |
440 |
|
<para> |
441 |
|
<inlinemediaobject> |
442 |
|
<imageobject> |
443 |
|
<imagedata fileref="../images/3_5_legend.png" format="PNG" scale="&imgscale;"/> |
444 |
|
</imageobject> |
445 |
|
<imageobject> |
446 |
|
<imagedata fileref="./images/3_5_legend.eps" format="EPS" scale="&imgscale;"/> |
447 |
|
</imageobject> |
448 |
|
<textobject> <phrase>Legend</phrase> </textobject> |
449 |
|
</inlinemediaobject> |
450 |
|
</para> |
451 |
<para> |
<para> |
452 |
|
The Legend provides an overview of the layers in the map. Layers |
453 |
|
that appear higher in the legend will appear ``closer'' to the user. |
454 |
|
If a layer supports classification (currently, only shape layers |
455 |
|
have this feature) then the classification groups will be shown |
456 |
|
below each layer. The properties for each group are also displayed |
457 |
|
with a small graphic. Polygon layers appear as rectangles, lines |
458 |
|
appear as curved lines, and points appear as circles. |
459 |
|
</para> |
460 |
|
<para> |
461 |
|
Along the top of the legend is a toolbar which allows quick access |
462 |
|
to some of the layer manipulation options under |
463 |
|
<menuchoice><guimenu>Map</guimenu></menuchoice>. |
464 |
|
</para> |
465 |
|
|
466 |
|
<itemizedlist> |
467 |
|
<listitem> |
468 |
|
<para> |
469 |
|
The Move Layer to Top tool |
470 |
|
<inlinemediaobject> |
471 |
|
<imageobject> |
472 |
|
<imagedata fileref="../images/3_5_totop.png" format="PNG" scale="&imgscale;"/> |
473 |
|
</imageobject> |
474 |
|
<imageobject> |
475 |
|
<imagedata fileref="./images/3_5_totop.eps" format="EPS" scale="&imgscale;"/> |
476 |
|
</imageobject> |
477 |
|
<textobject> <phrase>Move Layer to Top</phrase> </textobject> |
478 |
|
</inlinemediaobject> raises the selected layer to the top of the map. |
479 |
|
</para> |
480 |
|
</listitem> |
481 |
|
<listitem> |
482 |
|
|
483 |
|
<para> |
484 |
|
The Move Layer Up tool |
485 |
|
<inlinemediaobject> |
486 |
|
<imageobject> |
487 |
|
<imagedata fileref="../images/3_5_moveup.png" format="PNG" scale="&imgscale;"/> |
488 |
|
</imageobject> |
489 |
|
<imageobject> |
490 |
|
<imagedata fileref="./images/3_5_moveup.eps" format="EPS" scale="&imgscale;"/> |
491 |
|
</imageobject> |
492 |
|
<textobject> <phrase>Move Layer Up</phrase> </textobject> |
493 |
|
</inlinemediaobject> raises the selected layer one level. |
494 |
|
</para> |
495 |
|
</listitem> |
496 |
|
<listitem> |
497 |
|
|
498 |
|
<para> |
499 |
|
The Move Layer Down tool |
500 |
|
<inlinemediaobject> |
501 |
|
<imageobject> |
502 |
|
<imagedata fileref="../images/3_5_movedown.png" format="PNG" scale="&imgscale;"/> |
503 |
|
</imageobject> |
504 |
|
<imageobject> |
505 |
|
<imagedata fileref="./images/3_5_movedown.eps" format="EPS" scale="&imgscale;"/> |
506 |
|
</imageobject> |
507 |
|
<textobject> <phrase>Move Layer Down</phrase> </textobject> |
508 |
|
</inlinemediaobject> lowers the selected layer one level. |
509 |
|
</para> |
510 |
|
|
511 |
|
</listitem> |
512 |
|
<listitem> |
513 |
|
<para> |
514 |
|
The Move Layer to Bottom tool |
515 |
|
<inlinemediaobject> |
516 |
|
<imageobject> |
517 |
|
<imagedata fileref="../images/3_5_tobottom.png" format="PNG" scale="&imgscale;"/> |
518 |
|
</imageobject> |
519 |
|
<imageobject> |
520 |
|
<imagedata fileref="./images/3_5_tobottom.eps" format="EPS" scale="&imgscale;"/> |
521 |
|
</imageobject> |
522 |
|
<textobject> <phrase>Move Layer to Bottom</phrase> </textobject> |
523 |
|
</inlinemediaobject> lowers the selected layer to the bottom of the map. |
524 |
|
</para> |
525 |
|
|
526 |
|
</listitem> |
527 |
|
<listitem> |
528 |
|
<para> |
529 |
|
The Visible tool |
530 |
|
<inlinemediaobject> |
531 |
|
<imageobject> |
532 |
|
<imagedata fileref="../images/3_5_visible.png" format="PNG" scale="&imgscale;"/> |
533 |
|
</imageobject> |
534 |
|
<imageobject> |
535 |
|
<imagedata fileref="./images/3_5_visible.eps" format="EPS" scale="&imgscale;"/> |
536 |
|
</imageobject> |
537 |
|
<textobject> <phrase>Visible</phrase> </textobject> |
538 |
|
</inlinemediaobject> shows the selected layer in the map if it was |
539 |
|
hidden. |
540 |
|
</para> |
541 |
|
|
542 |
|
</listitem> |
543 |
|
<listitem> |
544 |
|
<para> |
545 |
|
The Invisible tool |
546 |
|
<inlinemediaobject> |
547 |
|
<imageobject> |
548 |
|
<imagedata fileref="../images/3_5_invisible.png" format="PNG" scale="&imgscale;"/> |
549 |
|
</imageobject> |
550 |
|
<imageobject> |
551 |
|
<imagedata fileref="./images/3_5_invisible.eps" format="EPS" scale="&imgscale;"/> |
552 |
|
</imageobject> |
553 |
|
<textobject> <phrase>Invisible</phrase> </textobject> |
554 |
|
</inlinemediaobject> hides the selected layer in the map. |
555 |
|
</para> |
556 |
|
|
557 |
|
</listitem> |
558 |
|
<listitem> |
559 |
|
<para> |
560 |
|
The Properties tool |
561 |
|
<inlinemediaobject> |
562 |
|
<imageobject> |
563 |
|
<imagedata fileref="../images/3_5_props.png" format="PNG" scale="&imgscale;"/> |
564 |
|
</imageobject> |
565 |
|
<imageobject> |
566 |
|
<imagedata fileref="./images/3_5_props.eps" format="EPS" scale="&imgscale;"/> |
567 |
|
</imageobject> |
568 |
|
<textobject> <phrase>Properties</phrase> </textobject> |
569 |
|
</inlinemediaobject> opens the layer's properties dialog box. |
570 |
|
Double-clicking on a layer or a group of a layer will open the |
571 |
|
properties dialog for that layer. |
572 |
</para> |
</para> |
573 |
|
</listitem> |
574 |
|
</itemizedlist> |
575 |
|
<para> |
576 |
|
Along the bottom of the legend is the scalebar. The scalebar |
577 |
|
will be available if there are any layers and the map has a |
578 |
|
projection set. |
579 |
|
</para> |
580 |
|
</section> |
581 |
|
|
582 |
|
<section><title>Exporting</title> |
583 |
|
<para> |
584 |
|
Under Windows, maps can be exported in Enhanced Metafile format |
585 |
|
(<varname>.wmf</varname>) |
586 |
|
from |
587 |
|
<menuchoice> |
588 |
|
<guimenu>Map</guimenu> |
589 |
|
<guimenuitem>Export</guimenuitem> |
590 |
|
</menuchoice> for use in reports, presentations, or further |
591 |
|
modification. The current map view, legend, and, if available, |
592 |
|
scalebar are exported. Under other platforms this option is not |
593 |
|
available. Clicking this menu item open a file selection dialog |
594 |
|
that lets the user select a location to export the map. |
595 |
|
</para> |
596 |
</section> |
</section> |
597 |
|
|
598 |
<section><title>Printing</title> |
<section><title>Printing</title> |
599 |
<para> |
<para> |
600 |
|
The map can be printed using |
601 |
|
<menuchoice> |
602 |
|
<guimenu>Map</guimenu> |
603 |
|
<guimenuitem>Print</guimenuitem> |
604 |
|
</menuchoice>. The current map view, legend, and, if available, |
605 |
|
scalebar are printed. A standard printing dialog will open allowing |
606 |
|
the user to configure the printer. This dialog will differ depending |
607 |
|
on which platform Thuban is running. |
608 |
</para> |
</para> |
609 |
</section> |
</section> |
610 |
|
|
611 |
</chapter> |
</chapter> |
612 |
|
|
613 |
<chapter><title>Layer Management</title> |
<chapter><title>Layer Management</title> |
614 |
<para> |
<para> |
615 |
</para> |
</para> |
616 |
|
|
617 |
<section><title>Layer types</title> |
<section><title>Types of Layers</title> |
618 |
<para> |
<para> |
619 |
|
There are two types of layers supported by Thuban: shape layers and |
620 |
|
image layers. Shape layers consist of vector based shapes with |
621 |
|
geo-referenced coordinates. There are three types of supported |
622 |
|
shapes: polygons, lines (arc), and points. Image layers can be any image |
623 |
|
file format supported by the Geo-spatial Data Abstraction Library |
624 |
|
(GDAL). The images must have geographic |
625 |
|
coordinate data either embedded within the file or in a separate |
626 |
|
file that is in the same directory as the image file. GeoTIFF files |
627 |
|
work very well with Thuban and were designed specifically to be image |
628 |
|
layers in GIS programs. |
629 |
</para> |
</para> |
630 |
|
<para> |
631 |
|
All actions in the |
632 |
|
<menuchoice> |
633 |
|
<guimenu>Layer</guimenu> |
634 |
|
</menuchoice> menu act on the currently selected layer in the legend. |
635 |
|
</para> |
636 |
</section> |
</section> |
637 |
|
|
638 |
<section><title>Visibility</title> |
<section><title>Properties</title> |
639 |
<para> |
<para> |
640 |
|
To view the properties for a layer it must first be selected in the |
641 |
|
legend. The menu option |
642 |
|
<menuchoice> |
643 |
|
<guimenu>Layer</guimenu> |
644 |
|
<guimenuitem>Properties</guimenuitem> |
645 |
|
</menuchoice> opens a dialog that displays a layer's properties. |
646 |
|
All layers have a title which can be modified in the text field |
647 |
|
provided. The type of layer is also shows. If the type is a type |
648 |
|
of shape (polygon, arc, point) the classification table will be |
649 |
|
shown. Image layers have no other properties other than title |
650 |
|
and type. |
651 |
|
</para> |
652 |
|
<para> |
653 |
|
<figure> |
654 |
|
<title>Properties Window</title> |
655 |
|
<mediaobject> |
656 |
|
<imageobject><imagedata fileref="../images/4_2_layer_properties.png" format="PNG" scale="&imgscale;"/></imageobject> |
657 |
|
<imageobject><imagedata fileref="./images/4_2_layer_properties.eps" format="EPS" scale="&imgscale;"/></imageobject> |
658 |
|
</mediaobject> |
659 |
|
</figure> |
660 |
|
</para> |
661 |
|
<para> |
662 |
|
<figure> |
663 |
|
<title>Properties Window</title> |
664 |
|
<mediaobject> |
665 |
|
<imageobject><imagedata fileref="../images/4_2_raster_layer_properties.png" format="PNG" scale="&imgscale;"/></imageobject> |
666 |
|
<imageobject><imagedata fileref="./images/4_2_raster_layer_properties.eps" format="EPS" scale="&imgscale;"/></imageobject> |
667 |
|
</mediaobject> |
668 |
|
</figure> |
669 |
</para> |
</para> |
670 |
</section> |
</section> |
671 |
|
|
672 |
<section><title>Sequence</title> |
<section><title>Visibility</title> |
673 |
<para> |
<para> |
674 |
|
Sometimes it is not desirable to view all layers at the same time. |
675 |
|
Some layers may take a long time to draw and so while navigating |
676 |
|
around the map the user may not want to wait for the map to redraw |
677 |
|
all the layers each time the map is changed. Each layer can be |
678 |
|
independently turned on or off using the |
679 |
|
<menuchoice> |
680 |
|
<guimenu>Layer</guimenu> |
681 |
|
<guimenuitem>Show</guimenuitem> |
682 |
|
</menuchoice> |
683 |
|
or |
684 |
|
<menuchoice> |
685 |
|
<guimenu>Layer</guimenu> |
686 |
|
<guimenuitem>Hide</guimenuitem> |
687 |
|
</menuchoice> options respectively. |
688 |
</para> |
</para> |
689 |
</section> |
</section> |
690 |
|
|
691 |
<section><title>Duplication</title> |
<section><title>Duplication</title> |
692 |
<para> |
<para> |
693 |
|
Layers and all their properties, including classifications, can |
694 |
|
be duplicated using |
695 |
|
<menuchoice> |
696 |
|
<guimenu>Layer</guimenu> |
697 |
|
<guimenuitem>Duplicate</guimenuitem> |
698 |
|
</menuchoice>. Duplicating a layer is useful if the user wishes |
699 |
|
to model a layer in several different ways. Even though the layers |
700 |
|
overlap, by carefully selecting the shape properties it is possible |
701 |
|
to display several pieces of information at once. For example, one |
702 |
|
copy of a roads layer may be classified on a length property and |
703 |
|
another copy may be classified on a type property. If the length |
704 |
|
property was expressed with color and the type property expressed |
705 |
|
with line thickness then it would be possible to view both |
706 |
|
classifications by placing the type property copy over the |
707 |
|
length property copy. |
708 |
</para> |
</para> |
709 |
</section> |
</section> |
710 |
|
|
|
<section><title>Properties</title> |
|
|
<para> |
|
|
</para> |
|
|
</section> |
|
711 |
</chapter> |
</chapter> |
712 |
|
|
713 |
<chapter><title>Layer Classifications</title> |
<chapter><title>Layer Classifications</title> |
714 |
<para> |
<para> |
715 |
|
A layer classification is a way of assigning drawing properties to |
716 |
|
groups of shapes based on attributes stored in the layer's table. |
717 |
|
Only layer's with shapes can have a classification; image layers |
718 |
|
cannot be classified. |
719 |
|
</para> |
720 |
|
<para> |
721 |
|
A classification consists of a number of groups, each group |
722 |
|
having a value or range of values to match against, and symbol |
723 |
|
properties which control how a shape is drawn on the map. The user |
724 |
|
selects which field in the table is used by the classification and |
725 |
|
when the map is drawn the value for that field for each shape is |
726 |
|
compared with each group's value. The properties of the first group |
727 |
|
to match are used to draw the shape. This allows the user to get a |
728 |
|
visual impression of not only how the data is laid out but also what |
729 |
|
kind of data lies where. |
730 |
|
</para> |
731 |
|
<para> |
732 |
|
A layer always has a classification. When a new layer is added to the |
733 |
|
map, a default classification is created with the DEFAULT group. This |
734 |
|
group cannot be removed but can be hidden (see below). Every shape in the |
735 |
|
layer, regardless of its attributes, will match this group if no other |
736 |
|
group matches. |
737 |
</para> |
</para> |
738 |
|
|
739 |
<section><title>Adding and removing classes</title> |
<section><title>Editing Classifications</title> |
740 |
<para> |
<para> |
741 |
|
A layer's classification can be modified under the properties dialog |
742 |
|
(<menuchoice> |
743 |
|
<guimenu>Layer</guimenu> |
744 |
|
<guimenuitem>Properties</guimenuitem> |
745 |
|
</menuchoice>). The layer's classification field can be set to None, |
746 |
|
which simply assigns a DEFAULT group to the classification. No new |
747 |
|
groups can be added to the classification if the field is None. |
748 |
|
The user must first select a field to classify on. New groups can |
749 |
|
be added to the classification with the <guibutton>Add</guibutton> |
750 |
|
button. |
751 |
|
</para> |
752 |
|
<para> |
753 |
|
To apply the changes to the map the user can click |
754 |
|
either <guibutton>Try</guibutton> or <guibutton>OK</guibutton>. |
755 |
|
<guibutton>Try</guibutton> will not close the dialog box, allowing |
756 |
|
the user to see how the classification changes the map. |
757 |
|
<guibutton>Revert</guibutton> will undo the last classification applied |
758 |
|
to the map. <guibutton>OK</guibutton> will commit the changes and |
759 |
|
close the dialog. The user will be unable to undo the changes. |
760 |
|
<guibutton>Close</guibutton> simply closes the dialog box. If any |
761 |
|
changes have not been applied with <guibutton>Try</guibutton> the |
762 |
|
changes will not be applied to the map. |
763 |
|
</para> |
764 |
|
<para> |
765 |
|
<figure> |
766 |
|
<title>Properties Window</title> |
767 |
|
<mediaobject> |
768 |
|
<imageobject><imagedata fileref="../images/5_classification.png" format="PNG" scale="&imgscale;"/></imageobject> |
769 |
|
<imageobject><imagedata fileref="./images/5_classification.eps" format="EPS" scale="&imgscale;"/></imageobject> |
770 |
|
</mediaobject> |
771 |
|
</figure> |
772 |
|
</para> |
773 |
|
<para> |
774 |
|
The order of the groups in the classification is significant |
775 |
|
except for the DEFAULT group, which remains at the top. When shapes |
776 |
|
are matched against groups the matching begins at the first group |
777 |
|
after the DEFAULT group so that groups higher in the list will |
778 |
|
be checked first. Matching for a |
779 |
|
given shape will stop at the first group that matches. The user can |
780 |
|
use <guibutton>Move Up</guibutton> and <guibutton>Move Down</guibutton> |
781 |
|
to change the order of the groups. The DEFAULT group will always |
782 |
|
match a shape that hasn't matched another group. |
783 |
</para> |
</para> |
784 |
|
<section><title>Visible</title> |
785 |
|
<para> |
786 |
|
The Visible column has check-boxes that determine whether a |
787 |
|
classification group will be displayed in the legend. This is |
788 |
|
useful if the user knows that the groups completely cover |
789 |
|
the data set and don't want the DEFAULT group to be displayed |
790 |
|
in the legend and on a printout. |
791 |
|
</para> |
792 |
|
</section> |
793 |
|
<section><title>Symbols</title> |
794 |
|
<para> |
795 |
|
Each type of shape has its own type of symbol. Thuban supports three |
796 |
|
types of shapes: polygons, lines, and points. Polygons and points |
797 |
|
have outline and fill color, while lines have only line color. Each |
798 |
|
group has associated symbol properties. To edit the symbol |
799 |
|
properties for a group the user can double click on the Symbol |
800 |
|
column or select a group and click the |
801 |
|
<guibutton>Edit Symbol</guibutton> button. |
802 |
|
</para> |
803 |
|
</section> |
804 |
|
<section><title>Value</title> |
805 |
|
<para> |
806 |
|
The Value column of the classification table is the value that will |
807 |
|
be matched when the map is being drawn. The type of data that can |
808 |
|
entered into this field depends on the type of data of the |
809 |
|
classification field. |
810 |
|
</para> |
811 |
|
<para> |
812 |
|
If the field is of type Text, anything entered |
813 |
|
into the field is valid. The text will be compared literally to the |
814 |
|
value of the shape attribute, including case sensitivity. |
815 |
|
If the type is Integer, then any valid integer may be entered. In |
816 |
|
addition, with special syntax, a range of values can be entered. |
817 |
|
A range from <varname>start</varname> to <varname>end</varname> |
818 |
|
inclusive is specified like this: <literal>[start;end]</literal>. |
819 |
|
The exclusive range is specified like this: |
820 |
|
<literal>]start;end[</literal>. Ranges can include infinity like |
821 |
|
this: <literal>[-oo;oo]</literal>. Field types can also be of type |
822 |
|
Decimal. They represent any rational number and can be used in |
823 |
|
ranges as well. |
824 |
|
</para> |
825 |
|
</section> |
826 |
|
<section><title>Label</title> |
827 |
|
<para> |
828 |
|
By default, the text that is displayed for a group in the legend |
829 |
|
is the value for that group. The label can substitute a more |
830 |
|
descriptive term in the legend. |
831 |
|
</para> |
832 |
|
</section> |
833 |
</section> |
</section> |
834 |
|
|
835 |
<section><title>Editing symbols</title> |
<section><title>Generating Classes</title> |
836 |
<para> |
<para> |
837 |
|
<figure> |
838 |
|
<title>Generate Class</title> |
839 |
|
<mediaobject> |
840 |
|
<imageobject><imagedata fileref="../images/5_3_genclass.png" format="PNG" scale="&imgscale;"/></imageobject> |
841 |
|
<imageobject><imagedata fileref="./images/5_3_genclass.eps" format="EPS" scale="&imgscale;"/></imageobject> |
842 |
|
</mediaobject> |
843 |
|
</figure> |
844 |
</para> |
</para> |
|
</section> |
|
|
|
|
|
<section><title>Automatic generation of classes</title> |
|
845 |
<para> |
<para> |
846 |
|
Creating a classification by hand can be tedious. |
847 |
|
Thuban, therefore, provides a means of generating an entire |
848 |
|
classification at once while still giving the user control over |
849 |
|
how it appears. Clicking <guibutton>Generate Class</guibutton> |
850 |
|
opens the <varname>Generate Classification</varname> dialog. |
851 |
|
Under the <varname>Generate</varname> pull down there are at most |
852 |
|
three different ways to generate classifications: |
853 |
|
Unique Values, Uniform Distribution, and Quantiles. Some options |
854 |
|
may not be available if the data type for the field does not |
855 |
|
support them. For instance, <varname>Uniform Distribution</varname> |
856 |
|
doesn't make sense for a Text field. |
857 |
</para> |
</para> |
858 |
|
<para> |
859 |
|
For every way of generating a classification, a color scheme must |
860 |
|
be selected. Thuban provides several different color schemes that |
861 |
|
affect how the group properties change over the classification. |
862 |
|
It may be desirable that only certain properties change over the |
863 |
|
classification. If the shape type is a polygon or a point then |
864 |
|
the <guibutton>Fix Border Color</guibutton> option will be available. |
865 |
|
This allows the user to select a border color for all classification |
866 |
|
groups. |
867 |
|
It is also possible to create a custom color scheme. Selecting |
868 |
|
this option will display two symbols: the one of the left has the |
869 |
|
properties of the first group and the one on the right has the |
870 |
|
properties of the last group. Thuban will interpolate between these |
871 |
|
two properties to generate the other groups. |
872 |
|
<figure> |
873 |
|
<title>Custom Color Scheme</title> |
874 |
|
<mediaobject> |
875 |
|
<imageobject><imagedata fileref="../images/5_2_custom_ramp.png" format="PNG" scale="&imgscale;"/></imageobject> |
876 |
|
<imageobject><imagedata fileref="./images/5_2_custom_ramp.eps" format="EPS" scale="&imgscale;"/></imageobject> |
877 |
|
</mediaobject> |
878 |
|
</figure> |
879 |
|
</para> |
880 |
|
<para> |
881 |
|
The Unique Values option lets the user select specific values that |
882 |
|
appear in the table. Clicking <guibutton>Retrieve From Table</guibutton> |
883 |
|
searches the table for all unique values and displays them in the |
884 |
|
list on the left. Items can be selected and moved to the list on the |
885 |
|
right. Each list can be sorted or reversed for easier searching. |
886 |
|
The classification that is generated will be in the same order as |
887 |
|
the list on the right. |
888 |
|
<figure> |
889 |
|
<title>Unique Values</title> |
890 |
|
<mediaobject> |
891 |
|
<imageobject><imagedata fileref="../images/5_2_unique_values.png" format="PNG" scale="&imgscale;"/></imageobject> |
892 |
|
<imageobject><imagedata fileref="./images/5_2_unique_values.eps" format="EPS" scale="&imgscale;"/></imageobject> |
893 |
|
</mediaobject> |
894 |
|
</figure> |
895 |
|
</para> |
896 |
|
<para> |
897 |
|
The Uniform Distribution option creates a user specified number of |
898 |
|
groups of ranges such that each range covers equal intervals. The |
899 |
|
minimum and maximum values can automatically be retrieved from the |
900 |
|
table by clicking <guibutton>Retrieve From Table</guibutton>. The |
901 |
|
stepping is how large each interval is. Adjusting this value will |
902 |
|
automatically recalculate how many groups is appropriate. |
903 |
|
<figure> |
904 |
|
<title>Uniform Distribution</title> |
905 |
|
<mediaobject> |
906 |
|
<imageobject><imagedata fileref="../images/5_2_uniform_dist.png" format="PNG" scale="&imgscale;"/></imageobject> |
907 |
|
<imageobject><imagedata fileref="./images/5_2_uniform_dist.eps" format="EPS" scale="&imgscale;"/></imageobject> |
908 |
|
</mediaobject> |
909 |
|
</figure> |
910 |
|
</para> |
911 |
|
<para> |
912 |
|
The Quantiles option generates ranges based on the number of items |
913 |
|
in the table. For example, by specifying five groups Thuban will |
914 |
|
generate five groups with appropriate ranges such that 20% of the table |
915 |
|
data is in each group. If it is impossible to generate exact |
916 |
|
groupings, Thuban will issue a warning but allow the user to continue. |
917 |
|
<figure> |
918 |
|
<title>Quantiles</title> |
919 |
|
<mediaobject> |
920 |
|
<imageobject><imagedata fileref="../images/5_2_quantiles.png" format="PNG" scale="&imgscale;"/></imageobject> |
921 |
|
<imageobject><imagedata fileref="./images/5_2_quantiles.eps" format="EPS" scale="&imgscale;"/></imageobject> |
922 |
|
</mediaobject> |
923 |
|
</figure> |
924 |
|
</para> |
925 |
</section> |
</section> |
926 |
</chapter> |
</chapter> |
927 |
|
|
928 |
<chapter><title>Projection Management</title> |
<chapter><title>Projection Management</title> |
929 |
<para> |
<para> |
930 |
|
Projections control how the geographic data is displayed on the screen. |
931 |
|
If multiple layers are loaded into Thuban where the geographic data |
932 |
|
is in a different projection system, then the user must specify a |
933 |
|
projection for each layer. The user must also tell Thuban which |
934 |
|
projection the map is in. This can be the same as the layers or a different |
935 |
|
projection in which case the layers are reprojected into that space. |
936 |
|
The map projection can be set using |
937 |
|
<menuchoice> |
938 |
|
<guimenu>Map</guimenu> |
939 |
|
<guimenuitem>Projection</guimenuitem> |
940 |
|
</menuchoice> and the layer projection can be set using |
941 |
|
<menuchoice> |
942 |
|
<guimenu>Layer</guimenu> |
943 |
|
<guimenuitem>Projection</guimenuitem> |
944 |
|
</menuchoice>. |
945 |
|
<figure> |
946 |
|
<title>Projection Window</title> |
947 |
|
<mediaobject> |
948 |
|
<imageobject><imagedata fileref="../images/6_projection.png" format="PNG" scale="&imgscale;"/></imageobject> |
949 |
|
<imageobject><imagedata fileref="./images/6_projection.eps" format="EPS" scale="&imgscale;"/></imageobject> |
950 |
|
</mediaobject> |
951 |
|
</figure> |
952 |
|
</para> |
953 |
|
<para> |
954 |
|
Thuban is distributed with a sample collection of projections. The |
955 |
|
user can create new projections and make them available to all |
956 |
|
future Thuban sessions. They may also be exported and imported so |
957 |
|
that custom projections can be distributed. |
958 |
</para> |
</para> |
959 |
|
<section><title>Selecting a Projection</title> |
960 |
|
<para> |
961 |
|
The available projections are listed on the left. If the layer |
962 |
|
or map already has a projection it will initially be highlighted |
963 |
|
and will end with <varname>(current)</varname>. Selecting |
964 |
|
<varname><None></varname> will cause Thuban to use the data as |
965 |
|
it appears in the source file and will not use a projection. |
966 |
|
</para> |
967 |
|
</section> |
968 |
|
<section><title>Editing a Projection</title> |
969 |
|
<para> |
970 |
|
Whenever a projection is selected from the list its properties |
971 |
|
are displayed on the right. These properties can be changed |
972 |
|
and the changes saved to the selected projection using |
973 |
|
<guibutton>Update</guibutton>. Only a projection that comes |
974 |
|
from a file can be updated, so if the current layer's projection |
975 |
|
is selected, <guibutton>Update</guibutton> will be disabled. |
976 |
|
<guibutton>Add to List</guibutton> adds the projection to the |
977 |
|
list of available projections as a new entry, and thus makes it |
978 |
|
available to future Thuban sessions. Clicking <guibutton>New</guibutton> |
979 |
|
will create an entirely new, empty projection. The |
980 |
|
<guibutton>Remove</guibutton> button will permanently remove a |
981 |
|
projection from the list of available projections. |
982 |
|
</para> |
983 |
|
<para> |
984 |
|
To apply the selected projection to the map the user can click |
985 |
|
either <guibutton>Try</guibutton> or <guibutton>OK</guibutton>. |
986 |
|
<guibutton>Try</guibutton> will not close the dialog box, allowing |
987 |
|
the user to see how the projeciton changes the map. |
988 |
|
<guibutton>Revert</guibutton> will undo the last projection applied |
989 |
|
to the map. <guibutton>OK</guibutton> will commit the changes and |
990 |
|
close the dialog. The user will be unable to undo the changes. |
991 |
|
<guibutton>Close</guibutton> simply closes the dialog box. If no |
992 |
|
selection has been applied with <guibutton>Try</guibutton> the |
993 |
|
selection will not be applied to the map. |
994 |
|
</para> |
995 |
|
</section> |
996 |
|
<section><title>Importing/Exporting Projections</title> |
997 |
|
<para> |
998 |
|
The projections that appear in the list of available projections |
999 |
|
can be exported to another file that the user chooses. By selecting |
1000 |
|
one or more projections and clicking <guibutton>Export</guibutton> |
1001 |
|
the user will be able to select a file in which to store those |
1002 |
|
projections. |
1003 |
|
The file can then be distributed to other Thuban users. To import |
1004 |
|
a projection file the user can click <guibutton>Import</guibutton>. |
1005 |
|
The imported projections are added to the list and are then available |
1006 |
|
to the current session and any future Thuban sessions. |
1007 |
|
</para> |
1008 |
|
</section> |
1009 |
</chapter> |
</chapter> |
1010 |
|
|
1011 |
<chapter><title>Table Management</title> |
<chapter><title>Table Management</title> |
1012 |
<para> |
<para> |
1013 |
|
Thuban distinguishes two different types of tables: Attribute tables |
1014 |
|
(which belong to a layer) and normal data tables. Both provide |
1015 |
|
the same general functionality with the difference that actions on an |
1016 |
|
attribute table might also effect the map display. |
1017 |
</para> |
</para> |
1018 |
|
|
1019 |
|
<section><title>Table View</title> |
1020 |
|
<para> |
1021 |
|
<figure> |
1022 |
|
<title>Table View</title> |
1023 |
|
<mediaobject> |
1024 |
|
<imageobject><imagedata fileref="../images/7_1_table_view.png" format="PNG" scale="&imgscale;"/></imageobject> |
1025 |
|
<imageobject><imagedata fileref="./images/7_1_table_view.eps" format="EPS" scale="&imgscale;"/></imageobject> |
1026 |
|
</mediaobject> |
1027 |
|
</figure> |
1028 |
|
</para> |
1029 |
|
<para> |
1030 |
|
Thuban provides a standard dialog to display table contents, the |
1031 |
|
Table View. The view has five sections: The title, selections, |
1032 |
|
the table grid, export functions, and the status bar. |
1033 |
|
</para> |
1034 |
|
<para> |
1035 |
|
The title bar identifies the table with its name. |
1036 |
|
</para> |
1037 |
|
<para> |
1038 |
|
The selections box let the user perform simple analysis on the data |
1039 |
|
based on comparisons: The first choice must be a field identifier of |
1040 |
|
the table, the second choice determines the type of comparison. The |
1041 |
|
third choice can be either a specific value (interpreted as numerical |
1042 |
|
or string depending on the type of the first field) or a second field |
1043 |
|
identifier. Thus you can perform analysis like selecting all |
1044 |
|
records where <literal>population > 10000</literal> or |
1045 |
|
<literal>cars_per_inhabitant < bikes_per_inhabitant</literal> |
1046 |
|
(note that the field names are only explanatory, the dBase files |
1047 |
|
allow only 11 character field names). |
1048 |
|
|
1049 |
|
Selections can be combined either by applying a selection only on |
1050 |
|
a previously selected set of records or by adding the results of a |
1051 |
|
selection to a previous set. The default is that a selection replaces |
1052 |
|
earlier results. |
1053 |
|
</para> |
1054 |
|
<para> |
1055 |
|
The table grid shows the contents of the table (one record per row), |
1056 |
|
with highlighted selection results. Columns and rows can be resized. |
1057 |
|
</para> |
1058 |
|
<para> |
1059 |
|
The contents of a table can be exported into a file, either dBase |
1060 |
|
format (DBF) or comma separated values (CSV). The |
1061 |
|
<guibutton>Export</guibutton> button |
1062 |
|
raises a file dialog to specify a path and file name, the export type |
1063 |
|
is determined by the file extension (either .dbf or .csv). |
1064 |
|
|
1065 |
|
The <guibutton>Export Selection</guibutton> button works similarly |
1066 |
|
but exports only the selected records. |
1067 |
|
|
1068 |
|
The <guibutton>Close</guibutton> button closes the table view window. |
1069 |
|
This is different from the menu item |
1070 |
|
<menuchoice> |
1071 |
|
<guimenu>Table</guimenu> |
1072 |
|
<guimenuitem>Close</guimenuitem> |
1073 |
|
</menuchoice> which unloads the table from Thuban. |
1074 |
|
</para> |
1075 |
|
<para> |
1076 |
|
The status bar displays some statistics about the table and optional |
1077 |
|
selection results. |
1078 |
|
</para> |
1079 |
|
</section> |
1080 |
|
|
1081 |
|
<section><title>General Functionality (Menu Table)</title> |
1082 |
|
<para> |
1083 |
|
The general functions affect all tables open in Thuban. Attribute |
1084 |
|
tables are considered here as normal data tables (with the exception |
1085 |
|
that they cannot be closed). |
1086 |
|
</para> |
1087 |
|
<section><title>Open</title> |
1088 |
|
<para> |
1089 |
|
The |
1090 |
|
<menuchoice> |
1091 |
|
<guimenu>Table</guimenu> |
1092 |
|
<guimenuitem>Open</guimenuitem> |
1093 |
|
</menuchoice> |
1094 |
|
item raises a file dialog to let you select a |
1095 |
|
dBase file from the file system to be loaded into Thuban read-only. |
1096 |
|
On <guibutton>OK</guibutton> the selected file is loaded and a |
1097 |
|
table view is opened. |
1098 |
|
</para> |
1099 |
|
</section> |
1100 |
|
|
1101 |
|
<section><title>Close</title> |
1102 |
|
<para> |
1103 |
|
The |
1104 |
|
<menuchoice> |
1105 |
|
<guimenu>Table</guimenu> |
1106 |
|
<guimenuitem>Close</guimenuitem> |
1107 |
|
</menuchoice> |
1108 |
|
item raises a dialog listing the currently open |
1109 |
|
data tables |
1110 |
|
(loaded via |
1111 |
|
<menuchoice> |
1112 |
|
<guimenu>Table</guimenu> |
1113 |
|
<guimenuitem>Open</guimenuitem> |
1114 |
|
</menuchoice>). Selected tables are dereferenced on confirmation. |
1115 |
|
Since tables are opened read-only the contents of the tables are |
1116 |
|
not affected. |
1117 |
|
|
1118 |
|
Any open views of the tables are closed as well. |
1119 |
|
|
1120 |
|
Tables used in a join cannot be closed. |
1121 |
|
</para> |
1122 |
|
</section> |
1123 |
|
|
1124 |
|
<section><title>Rename</title> |
1125 |
|
<para> |
1126 |
|
<menuchoice> |
1127 |
|
<guimenu>Table</guimenu> |
1128 |
|
<guimenuitem>Rename</guimenuitem> |
1129 |
|
</menuchoice> changes the table title. |
1130 |
|
</para> |
1131 |
|
</section> |
1132 |
|
|
1133 |
|
<section><title>Show</title> |
1134 |
|
<para> |
1135 |
|
The |
1136 |
|
<menuchoice> |
1137 |
|
<guimenu>Table</guimenu> |
1138 |
|
<guimenuitem>Show</guimenuitem> |
1139 |
|
</menuchoice> |
1140 |
|
item raises a list of available tables (explicitly |
1141 |
|
loaded, attribute tables, results of a join). Selected tables are |
1142 |
|
show in tables views on <guibutton>OK</guibutton>. |
1143 |
|
</para> |
1144 |
|
</section> |
1145 |
|
|
1146 |
|
<section><title>Join</title> |
1147 |
|
<para> |
1148 |
|
<figure> |
1149 |
|
<title>Join Tables</title> |
1150 |
|
<mediaobject> |
1151 |
|
<imageobject><imagedata fileref="../images/7_2_5_join.png" format="PNG" scale="&imgscale;"/></imageobject> |
1152 |
|
<imageobject><imagedata fileref="./images/7_2_5_join.eps" format="EPS" scale="&imgscale;"/></imageobject> |
1153 |
|
</mediaobject> |
1154 |
|
</figure> |
1155 |
|
</para> |
1156 |
|
<para> |
1157 |
|
The |
1158 |
|
<menuchoice> |
1159 |
|
<guimenu>Table</guimenu> |
1160 |
|
<guimenuitem>Join</guimenuitem> |
1161 |
|
</menuchoice> |
1162 |
|
item raises a dialog to specify the two tables to be |
1163 |
|
joined. The join results in a new table named 'Join of "left table" |
1164 |
|
and "right table"'. |
1165 |
|
|
1166 |
|
The dialog lets you select the two tables to be joined and the two |
1167 |
|
fields the join has to be performed on. By default, the new |
1168 |
|
table contains only those records which are matched by the join. |
1169 |
|
|
1170 |
|
If you want to preserve the records of the left table you can |
1171 |
|
perform an outer join. The fields from the right table for records |
1172 |
|
not matched by the join are filled with <varname>None</varname> in |
1173 |
|
this case. |
1174 |
|
</para> |
1175 |
|
</section> |
1176 |
|
|
1177 |
|
</section> |
1178 |
|
<section><title>Attribute Tables</title> |
1179 |
|
<para> |
1180 |
|
To clearly separate between both types of tables (data and |
1181 |
|
attribute), Thuban provides functionality regarding the attribute |
1182 |
|
tables under the <menuchoice><guimenu>Layer</guimenu></menuchoice> menu. |
1183 |
|
</para> |
1184 |
|
|
1185 |
|
<section><title>Show Table</title> |
1186 |
|
<para> |
1187 |
|
<menuchoice> |
1188 |
|
<guimenu>Layer</guimenu> |
1189 |
|
<guimenuitem>Show Table</guimenuitem> |
1190 |
|
</menuchoice> |
1191 |
|
opens the attribute table of the currently active layer in a table |
1192 |
|
view. |
1193 |
|
|
1194 |
|
In addition to the functionality described above selections |
1195 |
|
affect also the map display: objects related to selected records |
1196 |
|
are highlighted. |
1197 |
|
</para> |
1198 |
|
</section> |
1199 |
|
|
1200 |
|
<section><title>Join Table</title> |
1201 |
|
<para> |
1202 |
|
Unlike the join described above, the join does not result in a |
1203 |
|
new table. The attribute table of the currently active layer is the |
1204 |
|
left table and other tables are joined to this table. The results of |
1205 |
|
the join are available for classification. |
1206 |
|
|
1207 |
|
As a consequence, the join cannot result in fewer |
1208 |
|
records than the source attribute table. The user is warned if the |
1209 |
|
right table does not fulfill this constraint. An outer join must be |
1210 |
|
used in such cases. |
1211 |
|
</para> |
1212 |
|
</section> |
1213 |
|
|
1214 |
|
<section><title>Unjoin Table</title> |
1215 |
|
<para> |
1216 |
|
As said above, a normal table cannot be closed while it is still |
1217 |
|
used in a join. While the joined table resulting from a join of |
1218 |
|
normal tables can be simply closed (and thereby dereferencing |
1219 |
|
the source tables), this is not possible for attribute tables. |
1220 |
|
|
1221 |
|
Hence joins on attribute tables must be solved explicitly. This is |
1222 |
|
what the |
1223 |
|
<menuchoice> |
1224 |
|
<guimenu>Layer</guimenu> |
1225 |
|
<guimenuitem>Unjoin Table</guimenuitem> |
1226 |
|
</menuchoice> |
1227 |
|
item is used for: The last join for the currently |
1228 |
|
active layer is solved. |
1229 |
|
</para> |
1230 |
|
</section> |
1231 |
|
</section> |
1232 |
</chapter> |
</chapter> |
1233 |
|
|
1234 |
<chapter><title>Trouble Shooting</title> |
<chapter><title>Trouble Shooting</title> |
1235 |
<para> |
<para> |
1236 |
|
Here are a few problems that users have encountered when first using Thuban. |
1237 |
|
</para> |
1238 |
|
<para> |
1239 |
|
|
1240 |
|
<itemizedlist> |
1241 |
|
<listitem> |
1242 |
|
<para>After adding two or more layers nothing is drawn in the map window. |
1243 |
|
</para> |
1244 |
|
<para> |
1245 |
|
This is probably because the layers have different projections. Projections |
1246 |
|
must be set on all layers and on the map itself if the layers' projections |
1247 |
|
are different. |
1248 |
|
</para> |
1249 |
|
</listitem> |
1250 |
|
|
1251 |
|
<listitem> |
1252 |
|
<para>Thuban crashes on startup with the error |
1253 |
|
<literal>NameError: global name 'False' is not defined</literal>. |
1254 |
|
</para> |
1255 |
|
<para> |
1256 |
|
<varname>True</varname> and <varname>False</varname> were only introduced |
1257 |
|
in Python 2.2.1. Thuban depends on at least Python 2.2.1. |
1258 |
|
</para> |
1259 |
|
</listitem> |
1260 |
|
|
1261 |
|
<listitem> |
1262 |
|
<para>After compiling Thuban, Thuban crashes with an error similar to |
1263 |
|
<literal> |
1264 |
|
ImportError: /usr/local//lib/thuban/Thuban/../Lib/wxproj.so: undefined symbol: __gxx_personality_v0 |
1265 |
|
</literal> |
1266 |
|
</para> |
1267 |
|
<para> |
1268 |
|
Thuban depends on the wxWindows library. If Thuban is compiled with an |
1269 |
|
incompatible version of the compiler than wxWindows was compiled with |
1270 |
|
this error may occur. Try compiling with a different version of the |
1271 |
|
compiler. |
1272 |
|
</para> |
1273 |
|
</listitem> |
1274 |
|
</itemizedlist> |
1275 |
|
</para> |
1276 |
|
<para> |
1277 |
|
If an error occurs Thuban will display a dialog indicating the error |
1278 |
|
before closing. The text should be copied and reported to the |
1279 |
|
<ulink url="http://thuban.intevation.org/bugtracker.html"> |
1280 |
|
Intevation bugtracker |
1281 |
|
</ulink>. |
1282 |
|
More information about the system is available from |
1283 |
|
<menuchoice><guimenu>Help</guimenu><guimenuitem>About</guimenuitem></menuchoice> box. |
1284 |
|
This should also be included in the bug report. |
1285 |
|
<figure> |
1286 |
|
<title>Error Dialog</title> |
1287 |
|
<mediaobject> |
1288 |
|
<imageobject><imagedata fileref="../images/8_int_error.png" format="PNG" scale="&imgscale;"/></imageobject> |
1289 |
|
<imageobject><imagedata fileref="./images/8_int_error.eps" format="EPS" scale="&imgscale;"/></imageobject> |
1290 |
|
</mediaobject> |
1291 |
|
</figure> |
1292 |
</para> |
</para> |
1293 |
|
|
1294 |
</chapter> |
</chapter> |
1295 |
|
|
1296 |
<appendix><title>Supported Data Sources</title> |
<appendix><title>Supported Data Sources</title> |
1297 |
<para> |
<para> |
1298 |
</para> |
</para> |
1299 |
|
<variablelist> |
1300 |
|
<varlistentry> |
1301 |
|
<term>Shapefile</term> |
1302 |
|
<listitem> |
1303 |
|
<para> |
1304 |
|
The Shapefile format has become a standard format for saving |
1305 |
|
geographic vector information. It supports polygons, lines, and |
1306 |
|
points. |
1307 |
|
|
1308 |
|
<ulink url="http://www.esri.com/library/whitepapers/pdfs/shapefile.pdf"> |
1309 |
|
Technical Specification. |
1310 |
|
</ulink> |
1311 |
|
</para> |
1312 |
|
</listitem> |
1313 |
|
</varlistentry> |
1314 |
|
|
1315 |
|
<varlistentry> |
1316 |
|
<term>dBase file</term> |
1317 |
|
<listitem> |
1318 |
|
<para> |
1319 |
|
dBase files are used to store the attributes for each layer. This |
1320 |
|
is closely associated with the Shapefile format. For detailed |
1321 |
|
specifications on the correct format of a dBase file used with |
1322 |
|
Thuban please see the Technical Specification for the Shapefile |
1323 |
|
format above. |
1324 |
|
</para> |
1325 |
|
</listitem> |
1326 |
|
</varlistentry> |
1327 |
|
|
1328 |
|
<varlistentry> |
1329 |
|
<term>Raster files</term> |
1330 |
|
<listitem> |
1331 |
|
<para> |
1332 |
|
Binding the GDAL library Thuban supports numerous raster file formats, |
1333 |
|
see <ulink url="http://www.remotesensing.org/gdal/formats_list.html"> |
1334 |
|
GDAL format list</ulink> for details.</para> |
1335 |
|
|
1336 |
|
<para>Most commonly used is the <emphasis>TIFF/GeoTIFF</emphasis> |
1337 |
|
format: Raster maps are provided as TIFF images, with an additional |
1338 |
|
"world file" storing the geographic reference (usually with an |
1339 |
|
extension ".tfw". |
1340 |
|
</para> |
1341 |
|
</listitem> |
1342 |
|
</varlistentry> |
1343 |
|
|
1344 |
|
</variablelist> |
1345 |
</appendix> |
</appendix> |
1346 |
|
|
1347 |
<appendix><title>Supported Projections</title> |
<appendix><title>Supported Projections</title> |
1348 |
<para> |
<para> |
1349 |
|
The following types of projections are directly support by |
1350 |
|
Thuban. The specific values for each are provided by the user |
1351 |
|
to create custom projections. Thuban comes with predefined |
1352 |
|
projections which are available through the Projections dialog. |
1353 |
|
</para> |
1354 |
|
<itemizedlist> |
1355 |
|
<listitem> |
1356 |
|
<para>Geographic</para> |
1357 |
|
<itemizedlist> |
1358 |
|
<listitem><para><literal>Ellipsoid</literal></para></listitem> |
1359 |
|
<listitem><para> |
1360 |
|
<literal>Source Data</literal>: either Degrees or Radians |
1361 |
|
</para></listitem> |
1362 |
|
</itemizedlist> |
1363 |
|
</listitem> |
1364 |
|
<listitem> |
1365 |
|
<para>Lambert Conic Conformal</para> |
1366 |
|
<itemizedlist> |
1367 |
|
<listitem><para><literal>Ellipsoid</literal></para></listitem> |
1368 |
|
<listitem><para><literal>Latitude of 1st standard parallel</literal></para></listitem> |
1369 |
|
<listitem><para><literal>Latitude of 2nd standard parallel</literal></para></listitem> |
1370 |
|
<listitem><para><literal>Central Meridian</literal></para></listitem> |
1371 |
|
<listitem><para><literal>Latitude of Origin</literal></para></listitem> |
1372 |
|
<listitem><para><literal>False Easting</literal> (meters)</para></listitem> |
1373 |
|
<listitem><para><literal>False Northing</literal> (meters)</para></listitem> |
1374 |
|
</itemizedlist> |
1375 |
|
</listitem> |
1376 |
|
<listitem> |
1377 |
|
<para>Transverse Mercator</para> |
1378 |
|
<itemizedlist> |
1379 |
|
<listitem><para><literal>Ellipsoid</literal></para></listitem> |
1380 |
|
<listitem><para><literal>Latitude</literal>of origin</para></listitem> |
1381 |
|
<listitem><para><literal>Longitude</literal>at central meridian</para></listitem> |
1382 |
|
<listitem><para><literal>Scale Factor</literal>at central meridian</para></listitem> |
1383 |
|
<listitem><para><literal>False Easting</literal> (meters)</para></listitem> |
1384 |
|
<listitem><para><literal>False Northing</literal> (meters)</para></listitem> |
1385 |
|
</itemizedlist> |
1386 |
|
</listitem> |
1387 |
|
<listitem> |
1388 |
|
<para>Universal Transverse Mercator</para> |
1389 |
|
<itemizedlist> |
1390 |
|
<listitem><para><literal>Ellipsoid</literal></para></listitem> |
1391 |
|
<listitem><para><literal>Zone</literal> |
1392 |
|
(can be guessed appling the Propose button)</para></listitem> |
1393 |
|
<listitem><para><literal>Southern Hemisphere</literal> flag</para></listitem> |
1394 |
|
</itemizedlist> |
1395 |
|
</listitem> |
1396 |
|
</itemizedlist> |
1397 |
|
|
1398 |
|
<para> |
1399 |
|
Thuban comes with a sample set of map projections for various |
1400 |
|
European countries. Apart from the basic projection they differ |
1401 |
|
especially in their parameterization: |
1402 |
|
</para> |
1403 |
|
<itemizedlist> |
1404 |
|
<listitem><para>Belgium Datum 1972 (Lambert Conic Conformal)</para> |
1405 |
|
</listitem> |
1406 |
|
|
1407 |
|
<listitem><para>Gauss-Boaga Zone 1 (Italy, Transverse Mercartor)</para> |
1408 |
|
</listitem> |
1409 |
|
|
1410 |
|
<listitem><para>Gauss-Krueger Zone 2 (Germany, Transverse Mercartor) |
1411 |
|
</para> |
1412 |
|
</listitem> |
1413 |
|
|
1414 |
|
<listitem><para>Reseau Geodesique Francaise |
1415 |
|
(France, Lambert Conic Conformal)</para> |
1416 |
|
</listitem> |
1417 |
|
|
1418 |
|
<listitem><para>UK National Grid (United Kingdom, Transverse Mercartor) |
1419 |
|
</para> |
1420 |
|
</listitem> |
1421 |
|
</itemizedlist> |
1422 |
|
|
1423 |
|
<para> |
1424 |
|
Thuban uses the comprehensive PROJ library for projections. PROJ provides |
1425 |
|
more than the four commonly used projections described above. If needed |
1426 |
|
Thuban can be easily extended to a new projection covered by PROJ. |
1427 |
</para> |
</para> |
1428 |
</appendix> |
</appendix> |
1429 |
|
|
1430 |
</book> |
</book> |
1431 |
|
|