This is an update to my previous post “WFS to PostGIS in 3 Steps”. Thanks to Even Rouault’s comments and improvements to GDAL, it is now possible to load Latin1-encoded WFS (like the one by data.wien.gv.at) into PostGIS in just one simple step.

To use the following instructions, you’ll have to get the latest GDAL (release-1600-gdal-mapserver.zip)

You only need to run SDKShell.bat to set up the environment and ogr2ogr is ready for action:

C:\Users\Anita>cd C:\release-1600-gdal-mapserver
C:\release-1600-gdal-mapserver>SDKShell.bat
C:\release-1600-gdal-mapserver>ogr2ogr -overwrite -f PostgreSQL PG:"user=myuser password=mypassword dbname=wien_ogd" "WFS:http://data.wien.gv.at/daten/geoserver/ows?service=WFS&request=GetFeature&version=1.1.0&typeName=ogdwien:BEZIRKSGRENZEOGD&srsName=EPSG:4326"

Thanks everyone for your comments and help!

WFS to PostGIS in 3 Steps

By underdark

2012-09-26

OpenGovermentData, PostGIS

14 Comments

This is a quick note on how to download features from a WFS and import them into a PostGIS database. The first line downloads a zipped Shapefile from the WFS. The second one unzips it and the last one loads the data into my existing “gis_experimental” database:

wget "http://data.wien.gv.at/daten/geoserver/ows?service=WFS&request=GetFeature&version=1.1.0&typeName=ogdwien:BEZIRKSGRENZEOGD&srsName=EPSG:4326&outputFormat=shape-zip" -O BEZIRKSGRENZEOGD.zip
unzip -d /tmp BEZIRKSGRENZEOGD.zip
shp2pgsql -s 4326 -I -S -c -W Latin1 "/tmp/BEZIRKSGRENZEOGD.shp" | psql gis_experimental

Now, I’d just need a loop through the WFS Capabilities to automatically fetch all offered layers … Ideas anyone?

Thanks to Tim for his post “Batch importing shapefiles into PostGIS” which was very useful here.

Update: Many readers have pointed out that ogr2ogr is a great tool for this kind of use cases and can do the above in one line. That’s true – if it works. Unfortunately, it is picky about the supported encodings, e.g. doesn’t want to parse ISO-8859-15. In such cases, the three code lines above can be a good alternative.

Leaflet, Stamen Toner and QGIS Server – An Intro

By underdark

2012-09-19

Leaflet, QGIS Server

8 Comments

Today’s post is a note-to-self on how to set up a really quick little Leaflet web map with Stamen’s “Toner” background and a WMS overlay served by QGIS Server.

Note the use of the map parameter when creating the QGIS Server WMS layer.

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>

<meta http-equiv="content-type" content="text/html; charset=utf-8" />
<meta http-equiv="content-language" content="en" />

<title>Leaflet, Stamen Toner and QGIS Server</title>

<link rel="stylesheet" href="http://leaflet.cloudmade.com/dist/leaflet.css" />
<link rel="stylesheet" href="my.css" type="text/css" />
 <!--[if lte IE 8]><link rel="stylesheet" href="http://leaflet.cloudmade.com/dist/leaflet.ie.css" /><![endif]-->

<script type="text/javascript" src="http://leaflet.cloudmade.com/dist/leaflet.js"></script>
<script type="text/javascript" src="http://maps.stamen.com/js/tile.stamen.js?v1.1.3"></script>
<script type="text/javascript">
function initialize() {
	var stamen = new L.StamenTileLayer("toner-lite");
	
	var myLayer = new L.TileLayer.WMS("http://10.101.21.28/cgi-bin/qgis_mapserv.fcgi", {
		map: "/usr/lib/cgi-bin/test/test.qgs",
		layers: 'mylayer',
		format: 'image/png',
		transparent: 'TRUE',
	});
	
	var map = new L.Map("map", {
		center: new L.LatLng(48.2,16.4),
		zoom: 13,
 		minZoom: 10,
 		maxZoom: 18,
		layers: [stamen,myLayer],
	});
}
</script>

</head>

<body onload="initialize()">
    <div id="map" class="map"></div>
</body>

</html>

With this my.css, the map will be displayed in “full screen”.

  div.map{
    display:block;
    position:absolute;
    top:0;
    left:0;
    width:100%;
    height:100%;
  }

Update

You can test an extended live example at http://anitagraser.github.com/Webmapping-Sandbox/leaflet.html

Exploring Mobility Data Using Time Manager

By underdark

2012-09-11

QGIS, spatio-temporal data, Visualization

4 Comments

Data from various vehicles is collected for many purposes in cities worldwide. To get a feeling for just how much data is available, I created the following video using QGIS Time Manager which has been shown at the Austrian Museum of Applied Arts “MADE 4 YOU – Design for Change”. It shows one hour of taxi tracks in the city of Vienna:

If you like the video, please go to http://www.ertico.com/2012-its-video-competition-open-vote and vote for it in the category “Videos directed at the general public”.

3 Reasons to Move Your QGIS Plugins to the New Repository

By underdark

2012-09-05

QGIS

7 Comments

Since the release of QGIS 1.8, Plugin Installer no longer includes the “add 3rd party repositories” button. This was an intentional design choice!
The new official plugin repository at plugins.qgis.org keeps everything in one place making it easier for users to find documentation and report issues. It will also provide many long-wanted features such as a rating system for plugins. You can already sort by number of downloads to discover the most popular plugins.
Last but not least: New users will not be able to discover your plugin if it is not in the repository.

Go ahead to plugins.qgis.org and upload your plugin now!

Introducing the Latest Style User Interface Improvements

By underdark

2012-08-15

QGIS

4 Comments

Yesterday, Martin Dobias announced that Arun’s GSoC work on QGIS symbology has been merged into the developer version. So let’s have a look at todays nightly-build!

I’ll step through the features mentioned in the announcement to see how they look and work:

1. Style manager has been greatly improved: grouping of symbols, tagging, “smart” groups (showing only symbols matching some criteria), search

On opening new Style Manager, we can already see that it has changed considerably: There are groups on the left, tags at the bottom and a search field in the upper right corner.

new Style Manager

New groups are created with the “+” button and styles can be added using the context menu:

adding a style to a group

2. Symbol selector and properties dialogs have been integrated to just one dialog, improving the usability a lot

Instead of opening tons of nested windows, complex styles can now be easily edited using the symbol layer tree on the left:

3. Style database is now stored in a SQLite database rather than an XML file for better scalability. You can import all your saved symbols and color ramps from ~/.qgis/symbology-ng-style.xml – from now they will be stored in ~/.qgis/symbology-ng-style.db.

Importing through Style Manager works like a charm. All styles will be imported into the given group.

importing previous style.xml

4. Style import improvements: load style directly from given URL, saving imported symbols into a group

Instead of giving a path to a style XML, it’s also possible to specify a URL. That’s a great step towards shared symbol libraries!

5. SVG fill: shows directories for easier traversal through the SVG directories

Definitely a plus! It’s now much easier to work with big SVG symbol collections.

What a great result of this year’s Google Summer of Code for QGIS. Give these new features a try! I already fell in love with them.

Stamen Maps for QGIS

By underdark

2012-07-21

QGIS

24 Comments

Stamen’s maps are amongst the most creative and beautiful OpenStreetMap visualizations and it would be great to have them as base maps in QGIS.

No problem! Nathaniel Kelso has already done all the work for us and we can download the extended OpenLayers plugin from his Github page. (There is a pull request in place to add Stamen to the default plugin too.)

Simply unpack the plugin into QGIS’ plugin folder. As you can see in the following screen shot, I’ve put it besides the “original” OpenLayers 0.6.2 plugin. In QGIS plugin manager, I then switched to Nathaniel’s version.

It adds the possibility to load Stamen’s Watercolor, Toner and Terrain tiles into the QGIS project:

Like all other OpenLayers layers, these can now be overlaid with more data such as this heatmap which is based on Twitter data I presented in a previous post, processed using Heatmap plugin and semi-transparently overlaid onto Stamen’s Toner map:

Physical Maps on QGIS Cloud

By underdark

2012-06-27

Cartography, QGIS

8 Comments

QGIS Cloud is a great cloud hosting service for QGIS Server by Sourcepole. After online registration and installation of an (experimental) plugin, QGIS projects can be uploaded to the cloud quite comfortably.

For a quick test, I tried to recreate the map from “Open Data for Physical Maps”. Right now, one of the limitations is that raster layers cannot be uploaded. Instead of the SRTM data, I therefore chose OCM landscape from OpenLayers plugin to provide some hillshade. The process of uploading data and publishing the project went smoothly and I didn’t encounter any problems.

You can explore the map online at qgiscloud.com/anitagraser/corine_austria.

Considering the complexity of the Corine dataset, rendering is quite fast – certainly much better than on my notebook.

Open Data for Physical Maps

By underdark

2012-06-17

Cartography, QGIS

8 Comments

Corine Land Cover is a European program to create a land cover inventory of Europe. The data is freely available and a valuable input for many analyses. In this post, we’ll be using it to create a physical map.

For the background, reused the hillshade presented in “Mapping Open Data With Open GIS”

Instead of the standard grayscale, I defined a sand-colored colormap that looks warmer and more natural:

On top of this hillshade, I put the Corine land cover layer. Instead of the official, rather bright colors I selected a more neutral color palette and varying transparency values: Water areas are drawn with no transparency while forests are set to 50 % and built-up areas to up to 80 % transparency. I also skipped classes such as “bare rock” by setting them to be totally transparent:

On top of the land cover, I added a river dataset and styled it with the same color used for water surfaces in the Corine layer. Obviously, this is an optional step. Big rivers are visible within the land cover data too.

After adding a mask and labels, the map is ready to add the finishing touches in Print Composer: Title, explanatory text and a scale bar. I decided against adding a legend to this particular map since I hope that the color choices are intuitive enough.

If you want to create your own physical map, you can use Corine Land Cover for European regions or the National Vegetation Classification in the U.S.

A Rainbow Gradient for QGIS Vectors

By underdark

2012-06-15

QGIS

3 Comments

Here’s a rainbow gradient for use with QGIS “Categorized” or “Graduated” vector renderer:

<!DOCTYPE qgis_style>
<qgis_style version="0">
  <symbols/>
  <colorramps>
    <colorramp type="gradient" name="rainbow">
      <prop k="color1" v="250,8,8,255"/>
      <prop k="color2" v="92,11,122,255"/>
      <prop k="stops" v="0.3;237,244,25,255:0.5;46,155,45,255:0.66;29,18,122,255:0.82;152,6,130,255"/>
    </colorramp>
  </colorramps>
</qgis_style>

(Save as .xml and import using QGIS Style Manager.)

I’ll put it on my QGIS Resources Github repository too. Soon.