はじめましょう

提供: OSGeo.JP Wiki
2009年8月14日 (金) 17:50時点におけるKayama (トーク | 投稿記録)による版

(差分) ←前の版 | 最新版 (差分) | 次の版→ (差分)
移動: 案内検索

Getting Started

This chapter gives a quick overview of installing QGIS, some sample data from the QGIS web page and running a first and simple session visualizing raster and vector layers. <P>


Installation

<P> Installation of QGIS is very simple. Standard installer packages are available for MS Windows and Mac OS X. For many flavors of GNU/Linux binary packages (rpm and deb) or software repositories to add to your installation manager are provided. Get the latest information on binary packages at the QGIS website at http://qgis.osgeo.org/download/ .

<P> Installation from source

<P> If you need to build QGIS from source, please refer to the coding and compiling guide available at http://qgis.osgeo.org/documentation/ . The installation instructions are also distributed with the QGIS source code.

<P>



Sample Data

<P> The user guide contains examples based on the QGIS sample dataset.

<P> The Windows installer has an option to download the QGIS sample dataset. If checked, the data will be downloaded to your My Documents folder and placed in a folder called GIS Database. You may use Windows Explorer to move this folder to any convenient location. If you did not select the checkbox to install the sample dataset during the initial QGIS installation, you can either

  • use GIS data that you already have;
  • download the sample data from the QGIS website http://qgis.osgeo.org/download; or
  • uninstall QGIS and reinstall with the data download option checked.

<P> For GNU/Linux and Mac OSX there are not yet dataset installation packages available as rpm, deb or dmg. To use the sample dataset download the file qgis_sample_data as ZIP or TAR archive from http://download.osgeo.org/qgis/data/ and unzip or untar the archive on your system. The Alaska dataset includes all GIS data that are used as examples and screenshots in the user guide, and also includes a small GRASS database. The projection for the QGIS sample dataset is Alaska Albers Equal Area with unit feet. The EPSG code is 2964.

<P>

PROJCS["Albers Equal Area",
    GEOGCS["NAD27",
        DATUM["North_American_Datum_1927",
            SPHEROID["Clarke 1866",6378206.4,294.978698213898,
                AUTHORITY["EPSG","7008"]],
            TOWGS84[-3,142,183,0,0,0,0],
            AUTHORITY["EPSG","6267"]],
        PRIMEM["Greenwich",0,
            AUTHORITY["EPSG","8901"]],
        UNIT["degree",0.0174532925199433,
            AUTHORITY["EPSG","9108"]],
        AUTHORITY["EPSG","4267"]],
    PROJECTION["Albers_Conic_Equal_Area"],
    PARAMETER["standard_parallel_1",55],
    PARAMETER["standard_parallel_2",65],
    PARAMETER["latitude_of_center",50],
    PARAMETER["longitude_of_center",-154],
    PARAMETER["false_easting",0],
    PARAMETER["false_northing",0],
    UNIT["us_survey_feet",0.3048006096012192]]


If you intend to use QGIS as graphical frontend for GRASS, you can find a selection of sample locations (e.g. Spearfish or South Dakota) at the official GRASS GIS website
http://grass.osgeo.org/download/data.php .


Sample Session

<P> Now that you have QGIS installed and a sample dataset available, we would like to demonstrate a short and simple QGIS sample session. We will visualize a raster and a vector layer. We will use the landcover raster layer qgis_sample_data/raster/landcover.img and the lakes vector layer qgis_sample_data/gml/lakes.gml.

<P> start QGIS

<P>

  • Start QGIS by typing: qgis at a command prompt.
  • Start QGIS using the Start menu or desktop shortcut, or double click on a QGIS project file.
  • Double click the icon in your Applications folder.

<P> Load raster and vector layers from the sample dataset

<P>

  1. Click on the mActionAddRasterLayerLoad Raster icon.
  2. Browse to the folder qgis_sample_data/raster/, select the ERDAS Img file landcover.img and click Open.
  3. If the file is not listed, check if the Filetype combobox at the bottom of the dialog is set on the right type, in this case "Erdas Imagine Images (*.img, *.IMG)"
  4. Now click on the mActionAddOgrLayerLoad Vector icon.
  5. In the new Add Vector Layer dialog click Browse.
  6. Browse to the folder qgis_sample_data/gml/, select "GML" from the filetype combobox, then select the GML file lakes.gml and click Open, then in Add Vector dialog click OK.
  7. Zoom in a bit to your favorite area with some lakes.
  8. Double click the lakes layer in the map legend to open the Layer Properties dialog.
  9. Click on the Symbology tab and select a blue as fill color.
  10. Click on the Labels tab and check the Display labels checkbox to enable labeling. Choose NAMES field as Field containing label.
  11. Click Apply.

<P>

<A NAME="fig:simple_session"></A><A NAME="55"></A>
Figure: A Simple QGIS Session

[clip=true, width=12cm]simple_session

<P> You can see how easy it is to visualize raster and vector layers in QGIS. Let's move on to the sections that follow to learn more about the

available functionality, features and settings and how to use them.