EIU QGIS Workshop

In QGIS, print maps and images are constructed using a print composer.

1. Create a print composition

  From the main menu, select Project >> New Print Composer.

•  A dialog will pop up asking for a title. I'll enter Chicago Crime Map.

The Print Composer will open in a separate window.

    2. Add a map

        From the main menu of the Print Composer, select Layout >> Add Map or click the Add new map button:

  Then click and drag to place a map frame on the composer. The map will appear as in the main QGIS window:

   3. Set the map scale and extent

 Interactive zooming is not available in print composer, so we'll need to change the map scale by hand.

• In the Item panel (top right), make sure the map is selected.

• In the bottom right, select the Item Properties tab

• Find the scale property and enter a value of 400,000 to zoom to a scale of 1:400,000.

    4. Pan to chicago

 Interactive panning is available, but needs to be enabled:

• From the main menu, select Layout >> Move Content
• You can now use your mouse to pan the map. Here's what mine looks like:

    5. Adjust symbology

        You can adjust your symbology at any time. For example, to make your point symbols smaller:

• Go back to the main map and change the symbol size
• Back in Print Composer, click Update preview (in the Item Properties tab)

  Here's my map after reducing the symbol size:

    6. Add a legend

  To add a legend, select Layout >> Add Legend or click the Add new legend button:

  Then draw a rectangle on the print composer. The legend will probably contain way too much information:

    7. Modify the legend

  Luckily it's really easy to remove items from a legend:

• Select the legend
• Select the Item Properties tab in the lower right panel.
• In the Legend Items group, uncheck Auto update.
• Select an item you wish to remove and click the minus-sign.

    8. Add a Grid

        It's also really easy to add a grid to a map:

• Select the map
• In the Item properties panel, look for the Grids section:

• Click the green plus sign to add a grid.
• Set the Coordinate Reference System (CRS) if necessary.
  • I've chosen choose Illinois State Plane East (EPSG 3529)
• Set the grid intervals as appropriate
  • The units of Illinois State Plane East is meters
  • I've chosen a grid spacing of 25km (=25,000 meters)
• Adjust other parameters as desired

    9. Etcetera

• One of the most useful options is to Lock layers on a map. This allows you to create another map in print composer with different layer visibility and symbology.

• To group items, select the items you want to group and select Layout >> Group or press Ctrl-G on your keyboard.
• QGIS has a smart guides feature which allows you to align objects as you move them around.
• Unfortunately, QGIS does not have compass roses or other North Arrow symbols (but a simple north arrow can be created manually).

Here's an example of a map created in Print Composer:

Try it out yourself to see what maps you can make. QGIS does a good job here, the possibilities are endless.