投影法の指定
Specifying a Projection
QGIS no longer sets the map CRS to the coordinate reference system of the first layer loaded. When you start a QGIS session with layers that do not have a CRS, you need to control and define the CRS definition for these layers. This can be done globally or project-wide in the CRS tab under Edit > mActionOptionsOptions (Gnome, OSX) or Settings > mActionOptionsOptions (KDE, Windows). See Figure <A HREF="#fig:crsdialog">24</A>. <P>
- Prompt for CRS
- Project wide default CRS will be used
- Global default CRS displayed below will be used
<P> The global default CRS proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs comes predefined in QGIS but can of course be changed, and the new definition will be saved for subsequent QGIS sessions.
<P>
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[clip=true, width=12cm]crsdialog
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<P> If you want to define the coordinate reference system for a certain layer without CRS information, you can also do that in the General tab of the raster (<A HREF="#label_generaltab"><IMG ALIGN="BOTTOM" BORDER="1" ALT="[*]"
SRC="/usr/share/latex2html/icons/crossref.png"></A>) and vector (<A HREF="#vectorgeneraltab"><IMG ALIGN="BOTTOM" BORDER="1" ALT="[*]" SRC="/usr/share/latex2html/icons/crossref.png"></A>) properties
dialog. If your layer already has a CRS defined, it will be displayed as shown in Figure <A HREF="#fig:vector_symbology"><IMG ALIGN="BOTTOM" BORDER="1" ALT="[*]"
SRC="/usr/share/latex2html/icons/crossref.png"></A>.<P>
