Spatial Galaxy

Qgis Then and Now

Fri, 18 Feb 2022 07:19:12 -0900

QGIS turns twenty this year. I wrote the first lines of code in mid-February of 2002.

As many of you may know, the first time the code compiled and ran, it could do one thing:

Connect to a PostGIS database and draw a vector layer.

This was the humble beginning of one of the most popular open source GIS applications. GRASS GIS is of course the grandaddy of open source GIS, but the 20th birthday of QGIS is a testament to its longevity and commitment of all those who have made it what it is today.

I did an analysis of the code using cloc, which counts the lines of code and displays a summary.

Qgis Landmark Events

Tue, 07 Dec 2021 10:19:12 -0900

QGIS has had a lot of landmark events in it’s development. Here are just a few, not necessarily in chronological order: It compiled and ran on Linux, displaying data from a PostGIS database Successfully ported the code to Windows Successfully ported the code to Mac GRASS integration Added on the fly projection and coordinate system support Python support, allowing plugins Print composer (now layout) Installers everywhere! msi, dmg, osgeo4w, linux packages Migration of the code from CVS -> SVN - Git Processing toolbox The API-breaking migration from Python 2.

Visualization of Early QGIS Development

Sat, 04 Dec 2021 13:45:27 -0900

Years ago (2011), Nathan Woodrow did a visualization of code commits between QGIS 1.6 and 1.7 using Gource. I wanted to contrast the slow beginning of QGIS in 2002 with the flurry of activity in recent years. Gource can analyze a git repository and display the activity. The video below begins with the very slow start of QGIS development in 2002. Since displaying all of QGIS activity using Gource would result in a long video no one would want to watch, I took a look at the time period from 2002 to mid-2004, then jumped to June of 2021.

About

Fri, 03 Dec 2021 20:34:54 -0900

Gary Sherman has a wide and varied background, including that of geologist, mining engineer, software engineer, publisher, and author. He has authored both technical books and articles, as well as fiction. In 2002, he founded the popular open source QGIS project and has published several books on the topic. For eight years, Gary was at the helm of Locate Press, publisher of books on open source software. Gary has published a number of novels as G.

Leaflet Day 14 - Image Overlay and Wrap-up

Mon, 11 Feb 2019 14:49:34 -0900

We end our series with a somewhat trivial, though interesting addition to our map and a special offer. Leaflet allows you to add an image that spans a specified region on the map. Here we add a picture of a little lost moose to the map. In this instance, it serves no purpose other than to show we can do it. The JavaScript code needed is: var imageUrl = "/images/calf_moose.png"; bounds = thetrail.

Leaflet Day 13 - Styling with a Plugin

Sun, 10 Feb 2019 12:59:24 -0900

Today we’ll take a look at another plugin—one that allows us to interactively change they style of features on our map: Leaflet.StyleEditor. This illustrates how we can customize our map by changing styles on the fly and also serves as a starting point for even more customization. Installing and Referencing the Plugin The web page for the plugin provides information on installing it. This requires getting the css, js, and image files in the proper location, then referencing them in our HTML file:

Leaflet Day 12 - Create a Leaflet Map from QGIS

Sat, 09 Feb 2019 08:08:49 -0900

Today we’ll use the qgis2web plugin to export from QGIS to Leaflet. The QGIS project, a location map for the third (in progress) Life on the Alaska Frontier novel, looks like this: Installing qgis2web The qgis2web plugin is installed like any other. Click on the Plugins->Manage and Install Plugins... menu item, click Not installed, and then find qgis2web in the list. Click the Install plugin button to complete the install.

Leaflet Day 11 - Plugins

Fri, 08 Feb 2019 05:37:46 -0900

At its core, Leaflet is designed to be lightweight. That being said, there are hundreds of third-party plugins available to extend and enhance the functionality of your web maps. Today we’ll illustrate adding a plugin to our map from Day 6. The L.Control.ZoomBar plugin adds a custom zoom control that allows us to draw a box around the area we want to zoom to, as well as adding a Home button to return to the initial map view.

Leaflet Day 10 - Adding a Link to a Popup

Wed, 06 Feb 2019 07:21:58 -0900

In this post we’ll add a link to the towns popup that will display the satellite view on Google Maps. The API for working with Google Maps URLs can be found here: https://developers.google.com/maps/documentation/urls/guide. To add a link to the town name in the popup, we modify the JavaScript code that creates the towns layer: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 var towns = L.

Leaflet Day 9 - Calculating Distance with Turf.js

Mon, 04 Feb 2019 08:02:03 -0900

Today we’re going to use Turf.js to calculate the distance between any two points along the trail. Turf.js is billed as providing “Advanced geospatial analysis for browsers and Node.js.” The distance calculated is a straight line (“as the crow flies”) distance rather than actual trail miles. Including Turf.js To calculate the distance we need to include Turf.js. Rather than install it locally, just add this line to the head of your HTML:

Leaflet Day 8 - Zoom to Feature

Fri, 01 Feb 2019 14:40:12 -0900

In this post we’ll add a zoom button to pan the map to one of the towns in the trail stops layer. Adding a Dropdown Box and Button The first thing to do is add the select element and a button to the HTML: <select id='zoombox'> </select> <input type="button" id="zoomTo" value="Zoom to town"> We’ll populate the options for the select element using the town GeoJSON. Creating a Dictionary and Populating the Select Box Next we loop through the towns in the GeoJSON layer and create a dictionary that maps the town name to its data, then add each as an option to a select element:

Leaflet Day 7 - Coordinates

Wed, 30 Jan 2019 06:39:24 -0900

In this post, we’ll do a couple of things: Clean up the display of coordinate precision in our popups Add the current coordinates to the map as the mouse moves Coordinate Precision Display The current map displays the latitude and longitude with seven decimal places. This is more than we need to see when displaying information about locations: Fixing this is easy to do using the JavaScript function toFixed.

Leaflet Day 6 - GeoPackage Layers

Mon, 28 Jan 2019 08:01:31 -0900

In this post we’ll switch gears and install Leaflet locally, then add a layer from a GeoPackage file. Installing Leaflet Up until now we’ve been using a hosted version of Leaflet. In other words, each time we load the map, a request is made to fetch the Leaflet CSS and JavaScript. There are a couple of ways to install Leaflet: download it from the website or install with npm. In both cases you’ll need to move leaflet.

Leaflet Day 5 - Working with Features

Sun, 27 Jan 2019 05:19:21 -0900

Today we’ll add towns along the trail route that are mentioned in the novels. I hesitate to call them towns, because in 1902, many of them consisted of a view indigenous people and sometimes a roadhouse. The method to add these locations will be to add a GeoJSON layer and loop through each town, adding a marker and popup with some info. The Data The data for the locations is from the GNIS database for Alaska, containing over 35,000 locations.

Leaflet Day 4 - Basemaps and Overlays

Sat, 26 Jan 2019 00:00:00 +0000

Today we’ll add some basemaps and a couple of controls to our map. So far we’ve been using OpenStreetMap as our back drop. There are a couple of tile servers that will give us a little more of a “back in the day” look. We’ll also add attribution to the map so we give credit where credit is due, as well as a scale bar. Complete code for the map can be viewed at the bottom of this post.

Leaflet Day 3 - The Trail

Fri, 25 Jan 2019 09:03:36 -0900

Background In 1902 the only way from the port of Valdez to the Fortymile gold fields was a nearly 400 mile trail through the Alaska wilderness. The Valdez-Eagle trail plays a key role in novels two and three. Adding the Trail to a Leaflet Map To add the trail to our map, we will convert it from a shapefile to GeoJSON. There is more than one way to do this—you could use ogr2ogr, but we chose to use QGIS, since it would not only convert it, but transform the coordinate system at the same time.

Leaflet Day 2 - Adding a Marker

Thu, 24 Jan 2019 06:13:17 -0900

I’m starting off slow, so today we’ll add a marker with some extra features. Since the map from yesterday is already centered on the big earthquake, lets add a marker there. Adding a Marker To create a marker, Leaflet uses the L.marker class: var earthquakeMarker = L.marker([61.346, -149.955]); This creates the marker, but it needs to be added to the map: earthquakeMarker.addTo(map); This gives us: Good so far, but looking at the map tells us nothing about the marker.

Two Weeks of Leaflet - Day 1

Wed, 23 Jan 2019 12:52:54 -0900

Background We at Locate Press have been working on a new book: Leaflet Cookbook, by Numa Gremling. The book is chock-full of over 300 pages of recipes and information to get the most of your web maps. The book is content complete and available as a preview. I’ve dabbled in Leaflet in the past, but only scratched the surface. So, I’ve decided to spend two weeks starting from the ground up and create a decent web map.

Plugin Builder 3.1

Wed, 02 Jan 2019 00:00:00 +0000

We’ve released version 3.1 of the Plugin Builder for QGIS 3.x. This version contains a number of bug fixes and performance enhancements. Here are some of the changes included since version 3.0.3: Fix issue with reload on generated plugins Move dialog creation to run method to improve startup performance Move help file generation files to proper method Include missing tags file Attempt to compile resources.qrc when plugin is generated (requires pyrcc5 in path) Set deployment directory in Makefile based on user OS (pb_tool is recommended over make) Check for valid URL format for tracker and repository Compiling Resource File If you have the resource compiler pyrcc5 in your path, the resource file will be compiled automatically when you generate your new plugin.

Where's my .qgis3 Folder?

Mon, 12 Mar 2018 00:00:00 +0000

There’s been several posts to GIS StackExchange along the lines of: Where’s my .qgis3 folder? Prior to QGIS 3, the .qgis/.qgis2 folder was found under your home directory. At version 3, the folder has moved to a more standard profile location for your operating system. There are a couple of ways to determine where the folder is located: Use the Settings->User Profiles->Open active profile folder menu item Use QgsApplication.qgisSettingsDirPath from Python or the console Here are the “standard” locations for Linux, Mac, and Windows, as found under your HOME directory:

Quick Guide to Getting Started with PyQGIS 3 on Windows

Tue, 13 Feb 2018 00:00:00 +0000

Getting started with Python and QGIS 3 can be a bit overwhelming. In this post we give you a quick start to get you up and running and maybe make your PyQGIS life a little easier. There are likely many ways to setup a working PyQGIS development environment—this one works pretty well. Contents Requirements Installing OSGeo4W Setting the Environment pb_tool Working on the Command Line IDE Example Workflow Creating a New Plugin Working with Existing Plugin Code Troubleshooting

Faking a Data Provider with Python

Fri, 13 Mar 2015 00:00:00 +0000

QGIS data providers are written in C++, however it is possible to simulate a data provider in Python using a memory layer and some code to interface with your data. Why would you want to do this? Typically you should use the QGIS data providers, but here are some reasons why you may want to give it a go: There is no QGIS data provider The generic access available through OGR doesn’t provide all the features you need You have no desire to write a provider in C++ No one will write a C++ provider for you, for any amount of money If you go this route you are essentially creating a bridge that connects QGIS and your data store, be it flat file, database, or some other binary format.

Plugin Builder 2.8.1

Mon, 23 Feb 2015 00:00:00 +0000

This minor update to the Plugin Builder allows you to choose where your plugin menu will be located. Previously your menu was placed under the Plugins menu. At version 2.8.1 you can choose from the following main menu locations: Plugins Database Raster Vector Web Plugins is the default choice when you open Plugin Builder. The value you choose is also written to the category field in your metadata.txt file.

Plugin Builder 2.8

Fri, 20 Feb 2015 00:00:00 +0000

Plugin Builder 2.8 is now available. This is a minor update that adds: Suggestion for setting up an issue tracker and creating a code repository Suggestion for a home page Tag selection from a list of current tags Documentation update, including information about using pb_tool to compile, deploy, and package your plugin New URLs for Plugin Builder’s home page and bug tracking Optional is now Recommended In previous versions the following items were “Optional” when creating a new plugin:

PyQGIS Resources

Sat, 18 Oct 2014 10:18:00 +0000

Here is a short list of resources available when writing Python code in QGIS. If you know of others, please leave a comment. Blogs/Websites In alphabetical order: GIS StackExchange Kartoza Linfiniti Lutra Consulting Nathan Woodrow Nyall Dawson Twitter #pyqgis Documentation Choose the version to match your QGIS install PyQGIS Cookbook QGIS API Example Code Existing plugins can be a great learning tool Code Snippets in the PyQGIS Cookbook Plugins/Tools Script Runner: Run scripts to automate QGIS tasks Plugin Builder: Create a starter plugin that you can customize to complete your own plugin Plugin Reloader: Allows you to reload a plugin from within QGIS pb_tool: Tool to compile and deploy your plugins Books PyQGIS Programmers Guide Geospatial Desktop: GIS Scripting (PDF)

A Quick Guide to Getting Started with PyQGIS on Windows

Thu, 09 Oct 2014 16:55:00 +0000

Getting started with Python and QGIS can be a bit overwhelming. In this post we give you a quick start to get you up and running and maybe make your PyQGIS life a little easier. There are likely many ways to setup a working PyQGIS development environment—this one works pretty well. Contents Requirements Installing OSGeo4W Setting the Environment Python Packages Working on the Command Line IDE Example Workflow Creating a New Plugin Working with Existing Plugin Code Troubleshooting

QGIS Development with Plugin Builder and pb_tool

Thu, 09 Oct 2014 09:50:00 +0000

The Plugin Builder is a great tool for generating a working plugin project that you can customize. One of the main tasks in the development cycle is deploying the plugin to the QGIS plugin directory for testing. Plugin Builder comes with a Makefile that can be used on Linux and OS X to aid in development. Depending on your configuration, the Makefile may work on Windows. To help in managing development of your projects, we’ve come up with another option—a Python tool called pb_tool, which works anywhere QGIS runs.

Why QGIS Class Names Start with Qgs

Sat, 29 Mar 2014 10:50:00 +0000

If you’re a developer, or have looked at the QGIS source code, you’ve likely noticed that most C++ classes in the project start with Qgs. Back before the dark ages of QGIS, Trolltech (now Digia) allowed you to reserve name prefixes for classes that used the Qt framework. Shortly afterwards, I reserved the gs prefix for my use, resulting in class names that start with Qgs. You might think this is based on some mangling of words like QGIS or perhaps GIS, but it was purely egocentric:

The PyQGIS Programmer's Guide

Tue, 11 Mar 2014 12:06:00 +0000

The PyQGIS Programmer’s Guide is now available in both paperback and PDF. A sample chapter is also available for download. The book is fully compatible with the QGIS 2.x series of releases. See locatepress.com for details.

PyQGIS Programmer's Guide Available

Sun, 05 Jan 2014 12:35:00 +0000

The preview release of the PyQGIS Programmer’s Guide is now available for purchase from Locate Press.

QGIS Training Opportunities

Tue, 10 Dec 2013 08:28:00 +0000

We’re planning a couple of training classes for March: Introduction to QGIS Extending QGIS with Python Each is a one day class and we plan to run them back to back. If you are local or just want to come to Alaska in March for some spring skiing, northern lights viewing, or to experience the equinox, please hop over to GeoApt and let us know so we can plan accordingly.

Getting Paths with PyQGIS

Wed, 06 Nov 2013 14:45:00 +0000

When writing plugins or scripts it is often necessary to get information about the paths QGIS is using. For example, if we are writing a plugin that uses Python templates to create output based on user actions, we need to know the path to our installed plugin so we can find the templates. Fortunately the API provides an easy way to get at the information; here are a few examples:

Welcome to New QGIS PSC Members

Sun, 25 Aug 2013 12:33:00 +0000

Nominations for the QGIS PSC closed at 00:00 UTC on August 25, 2013 [1]. With only one nominee for each role, the PSC unanimously moved to accept each without election. The QGIS PSC welcomes new members Anita Graser, Richard Duivenvoorde, and Jürgen Fischer. The PSC is now composed of: Chair - Gary Sherman Community Advisor - Otto Dassau Design Advisor - Anita Graser Financial and Marketing Advisor - Paolo Cavallini Infrastructure Manager - Richard Duivenvoorde Release Manager - Jürgen Fischer Technical Advisor - Marco Hugentobler Testing/QA Manager - Tim Sutton The new PSC members begin their terms immediately.

QGIS PSC Call for Nominations

Tue, 06 Aug 2013 12:10:00 +0000

The QGIS Project Steering Committee (PSC) has announced a call for nominations to fill three vacant positions: Design Advisor Infrastructure Manager Release Manager Nominations are open until August 24, 2013. For details on the PSC, vacancies, and how to nominate someone, see the [Call for Nominations August 2013] (http://hub.qgis.org/projects/quantum-gis/wiki/Call_for_Nominations_August_2013).

QGIS Back in the Day

Wed, 17 Apr 2013 00:00:00 +0000

Do you remember this? If so, you’ve been using QGIS a long time… OGR and PostGIS support No raster support Three widgets on the Symbology tab No symbology in the legend But you could use it handily on a 640x480 display.

New Version of the QGIS Script Runner Plugin

Mon, 18 Mar 2013 19:47:00 +0000

The Script Runner plugin allows you to manage and execute a collection of scripts in QGIS to automate tasks and perform custom processing. Version 0.6 of Script Runner has been released and includes these changes: Arguments can be passed to a script using keyword arguments Script output is logged to the Script Runner window Script output can be logged to disk Preferences dialog allows control of output and logging options Exceptions in scripts are displayed without interfering with console/logging output Context menu (right-click) to access script functions Edit script function uses system default editor or one you specify in preferences For a basic introduction to Script Runner see this post: Script Runner: A Plugin to Run Python Scripts in QGIS

Littering Your Python Path: The Road to Destruction

Wed, 05 Dec 2012 16:59:00 +0000

Well not quite destruction, but a bit of hair pulling… While working on an update to the Plugin Builder, I encountered a small problem. The Plugin Builder displays the version number in the title bar of its main window. After bumping the version number to 1.8.4 in all the requisite places, it still showed 1.8.3 when testing. Using grep on all the source files revealed no instance of 1.8.3 in any file.

QGIS Gains a Gold Sponsor

Thu, 04 Oct 2012 05:55:00 +0000

The Quantum GIS (QGIS) project is happy to announce that the Asia Air Survey Co., Ltd (AAS), a Japanese international consulting company, has become a Gold Sponsor. AAS has committed to providing 9,000 EUR (~$11,000 US) each of three years, beginning in November 2012. The AAS sponsorship is yet another indication that QGIS is a mature and stable project which continues to provide innovative open source GIS software. The QGIS Project Steering Committee (PSC) wishes to thank AAS for their continuing commitment.

QGIS Is Ten Years Old

Wed, 18 Jul 2012 15:08:00 +0000

It was ten years ago, on July 19, 2002, that QGIS was officially unveiled. That first release was primitive, supporting only PostGIS layers and having little in the way of navigation controls. Invoking the open source mantra of “release early and release often,” I announced it on Freshmeat and waited. Slowly it began to attract attention—not all of it positive. Some questioned why I was starting a new open source GIS project when there were others I could join.

What's New in QGIS Plugins

Mon, 16 Apr 2012 12:12:00 +0000

Here’s a summary of recent additions and updates to plugins in the QGIS repository. FlowMapper (0.1.1) - Generates flow lines between discreet nodes for depicting spatial interaction data (e.g. migration). Query By Example (0.2) - Select features by location. Item Browser (1.6.0) - Browse a multiple selection with auto-zooming to feature and an option to open feature form. Custom Launcher (1.1.0) - Customize your own actions to launch your preferred apps or commands within QGIS.

QGIS Plugin of the Week: qNote

Fri, 06 Apr 2012 08:59:00 +0000

This week we look at a newly arrived plugin named qNote. This plugin allows you to create a note and store it in a QGIS project file. When the project is loaded, the note is restored and can be viewed in the qNote panel. This little plugin provides a way to attach metadata to a project. Things you might want to include in a note are: Content of the project Purpose Area of interest Where the data came from Who created the project This information can be helpful when sharing a project or when you forget what you did six months after the fact.

Getting Support for QGIS

Thu, 05 Apr 2012 07:02:00 +0000

The QGIS project has a number of support channels. Like many open source projects, these are loosely coupled. Recently the forum was made read-only and this has prompted a number of questions and concerns about how to receive support. This post outlines the ways in which you can get your questions answered. Home Page The QGIS home page has links to all the documentation and community resources. The navigation panel on the left has links to both the Community resources and the manual.

QGIS Forum Is Closed---What Do You Think?

Sat, 31 Mar 2012 08:35:22 +0000

The forum (http://forum.qgis.org) has been closed for new registrations and marked read-only. Users have been encouraged to use http://gis.stackexchange.com instead. If you have an thoughts on the closure, good, bad, or otherwise, please comment.

Script Runner: A Plugin to Run Python Scripts in QGIS

Sun, 29 Jan 2012 17:24:34 +0000

Following up on my last post, Running Scripts in the Python Console, I created a plugin to simplify running scripts: The Script Runner plugin allows you to add your scripts to a list so they are readily available. You can then run them to automate QGIS tasks and have full access to the PyQGIS API. In addition, you can view information about the classes, methods, and functions in your module as well as browse the source:

QGIS: Running Scripts in the Python Console

Fri, 27 Jan 2012 08:10:51 +0000

The QGIS Python console is great for doing one-off tasks or experimenting with the API. Sometimes you might want to automate a task using a script, and do it without writing a full blown plugin. Currently QGIS does not have a way to load an arbitrary Python script and run it.[1] Until it does, this post illustrates a way you can create a script and run it from the console.

Using the QGIS Raster Calculator

Wed, 25 Jan 2012 09:12:44 +0000

The raster calculator allows you to perform mathematical operations on each cell in a raster. This can be useful for converting and manipulating your rasters. Operators include: Mathematical (+, -, *, /) Trigonometric (sin, cos, tan, asin, acos, atan) Comparison (<, >, =, <=, >=) Logical (AND, OR) To perform operations on a raster or rasters, they must be loaded in QGIS.

QGIS Plugin of the Week: OpenLayers

Sat, 14 Jan 2012 08:28:14 +0000

This week we look at the OpenLayers plugin for QGIS. This plugin allows you to add a number of image services to your map canvas: Google Physical Streets Hybrid Satellite OpenStreetMap Yahoo Street Hybrid Satellite Bing Road Aerial Aerial with labels Installing the Plugin The OpenLayers plugin is installed like all other Python plugins. From the the Plugins menu in QGIS, choose Fetch Python Plugins.

QGIS Plugin of the Week: Profile

Fri, 06 Jan 2012 09:58:07 +0000

This week we take a look at a how to plot a terrain profile using the Profile plugin. The plugin can be used with any raster format supported by QGIS. You can can display profiles from up to three rasters at once, allowing you to compare the results. To illustrate, we’ll create a simple profile using a DEM of a 1:63,360 quadrangle in Alaska. Installing the Plugin The Profile plugin is installed like all other Python plugins.

QGIS Plugin of the Week: Points to Paths

Fri, 30 Dec 2011 09:43:58 +0000

This week we highlight the Points to Paths plugin, a handy way to convert a series of points into line features. This plugin lets you “connect the dots” based on an common attribute and a sequence field. The attribute field determines which points should be grouped together into a line. The sequence field determines the order in which the points will connected. The output from this plugin is a shapefile.

QGIS Plugin of the Week: Time Manager

Fri, 23 Dec 2011 10:26:26 +0000

QGIS has a lot of plugins, including over 180 that have been contributed by users. If you aren’t using plugins, you are missing out on a lot that QGIS has to offer. I’m starting what I hope to be a regular feature: Plugin of the Week. This week we’ll take a look at Time Manager. Time Manager lets you browse spatial data that has a temporal component. Essentially this includes anything that changes location through time.

QGIS Users Around the World

Mon, 19 Dec 2011 08:21:09 +0000

One of the difficult things to track in the open source world is the number of people who actually use your software. In the proprietary commercial world you have licenses, invoices, and so forth. In the case of QGIS, we can track the total number of downloads from qgis.org, but this doesn’t represent the total installed base. It is impossible to accurately determine the actual number of people using QGIS, but we can get an approximation of the number and where they are in the world.

Using git With Multiple QGIS Branches

Mon, 14 Nov 2011 09:03:15 +0000

This post is for those of you that build QGIS on a regular basis and want to keep up with everything going on in the current release branches (1.7.2 and 1.8) as well as the master branch that will eventually become version 2.0. While you can do all your work in one clone, this method has a couple of advantages, at the expense of a bit of disk space: Quicker compiles compared to branch switching, especially if you are using ccache Less likelihood of making a merge mess when switching branches The basic steps are:

Using the QGIS Plugin Builder

Thu, 27 Oct 2011 07:14:55 +0000

The Plugin Builder allows you to quickly create a skeleton Python plugin by generating all that boring boilerplate that every plugin requires. Here is a short video showing how to create, compile, and install a new plugin. For more information, see QGIS Workshop Documentation and the PyQGIS Cookbook.

Search QGIS IRC Logs

Sat, 24 Sep 2011 08:13:20 +0000

I added a simple feature that allows you to search the IRC logs from #qgis back to May 10, 2006. The search is case sensitive and will return a list of all matches. Not too smart but it will get you close to what you want. See the link at http://irclogs.geoapt.com/qgis

History of QGIS Committers

Fri, 23 Sep 2011 07:20:35 +0000

Using the git log leading up to the 1.7 release (June 2011) I put together a graphic that shows the growth of committers working on the project. In 2002 we had two people (me alone up until October). You can see significant jumps in developer interest in 2004 and 2008: In 2004 there were a number of releases that added significant functionality Following an announcement at FOSS4G 2007 in Victoria we released 0.

Importing a DBF containing X-Y Values into QGIS

Sat, 29 Jan 2011 10:49:16 +0000

Suppose you have a DBF (.dbf) file containing X and Y values that you want to import and save as a spatial layer. QGIS doesn’t support direct import of a DBF file as a map layer, however, we can use some command line magic to convert it to a CSV file and then use the Delimited Text plugin to get the job done. Your DBF file should have an id for each record and fields containing X and Y values.

Developing QGIS Plugins with git

Mon, 24 Jan 2011 17:40:03 +0000

Writing a QGIS plugin is not overly complicated but represents a bit of work. Using git in conjunction with your development efforts can make sure your investment in coding time is preserved. Development Tools The QGIS project team has set up a central location for plugin development which includes pretty much everything you need to develop and support your plugins, including: Issue tracking Wiki Documents

Evolution of QGIS

Mon, 03 Jan 2011 08:27:23 +0000

An interesting visualization of QGIS development over the last eight years: http://woostuff.wordpress.com/2011/01/03/generating-a-gource-source-commit-history-visualization-for-qgis-quantum-gis/

Contributing to QGIS Using Git

Mon, 27 Dec 2010 07:43:24 +0000

One of the challenges in any open source project is accepting contributions from people that don’t have, need, or want access to your centralized source code repository. Managing repository accounts for occasional or one-time contributors can be come a bit of an administrative issue. To date, the QGIS project has accepted one-time or occasional contributions through patches submitted via a help ticket. To make it easier for you to contribute to QGIS, we have created a clone of the Subversion repository on GitHub.

GeoApt Spatial Data Browser

Wed, 15 Dec 2010 16:25:10 +0000

This is a project I have had lingering around for a while. It is a geospatial data browser written in Python using the PyQt and QGIS bindings. It allows you to navigate a tree structure and preview raster and vector datasets. Metadata extracted from the data can be viewed as well. It supports drag and drop for any target that accepts filenames (e.g. QGIS). For screenshots and more, see http://geoapt.com/geoapt-data-browser.

Sherman's Law

Tue, 06 Apr 2010 10:36:30 +0000

In any sufficiently aged bureaucracy, process overshadows product.

Git Merge - No Problem

Sun, 04 Apr 2010 18:13:51 +0000

Using Git with Subversion makes adding new features easy. Here are the metrics for my latest QGIS hack: SVN revisions by others while working on my branch: 177 Time to complete merge with latest SVN revision: 1 second Conflicts: None Coincidence? Maybe not.

Google Summer of Code 2010 - Quantum GIS

Fri, 02 Apr 2010 15:28:28 +0000

The application deadline for the Google Summer of Code is nearing (April 9). If you are interested in working on QGIS as part of GSOC and need ideas, please see Quantum GIS Wiki. We are waiting for your proposal!

Vim and CMake Out-of-Source Builds

Tue, 30 Mar 2010 19:48:18 +0000

If you use Vim you probably know you can use the make command to build your project. The make command looks for a Makefile in your current directory. If you are editing a file that is not in the current directory (meaning you use some Vim magic to change to the directory containing your edit buffer), make will start below the top-level of your build directory. This is often the case when doing an out-of-source build with CMake.

Speculations on the File Geodatabase API

Sun, 28 Mar 2010 06:52:15 +0000

At the ESRI Developer Summit there was news of the File Geodatabase (FGDB) API. Based on the tweets from the summit it appears: The API will be C++ only API works on Windows and Unix/Linux (specifically RedHat, Solaris, SuSE) operating systems Rudimentary support only—features such as annotation, relationships, topologies, etc. are lacking Since ESRI is releasing a targeted API and a not a specification, support for Mac OS X is out of the question.

Everything You Have Done is Wrong

Sun, 28 Mar 2010 06:05:48 +0000

It’s true—everything you have ever done is wrong. If you are a developer, look at the code you wrote five years ago—it’s wrong. If you collect and store data—it’s wrong. This is the nature of human endeavor. The world used to be flat. The earth used to be the center of the universe. Discovery and development is an iterative process. What we do today will likely be replaced tomorrow. Just because we can’t be perfect at the outset doesn’t mean we shouldn’t try.

GIS for the UN*X World

Wed, 06 Jan 2010 19:40:32 +0000

In a recent post on VerySpatial.com, Jesse was discussing the apparent dominance of U*nix and observed: ‘…the geospatial industry almost completely left behind support for UNIX-like OSes’ It is true that the proprietary GIS vendors have largely abandoned Unix and Unix-like operating systems and continue to do so. However the open source GIS community has embraced all major operating systems with software that runs on Linux, *BSD, Mac OS X, and yes, Windows.

The Shapefile - Reports of My Deprecation have been Greatly Exaggerated

Mon, 04 Jan 2010 18:43:00 +0000

The death of the shapefile has again been predicted—this time for 2010. The technical description of the format has been around for going on 12 years. In that time it has become a sort of lowest common denominator for data exchange. They’re everywhere. Making them go away is going to require a revolution of sorts. ESRI has been sounding the death knell for the shapefile for a while now. I agree that it isn’t a perfect format but it is nearly perfectly supported.

What's Holding Back the Adoption of Open Source GIS on the Desktop?

Sat, 02 Jan 2010 20:33:28 +0000

In my last post I created a poll to get an idea of the extent of migration to open source GIS on the desktop. The results indicated that nearly 50% of the people using open source GIS were still using their proprietary software as well. You can view the results of the poll using the Polls Archive link below the current poll. This leads one to wonder if it is the state of the open source software or other reasons that prevent a full migration.

Migrating to Open Source GIS on the Desktop

Fri, 20 Nov 2009 05:41:34 +0000

I keep seeing more evidence that many people and organizations are migrating to open source GIS on the desktop. In many cases a mix of proprietary and open source GIS is in use. I’m wondering about other’s experiences in this area. To gain some insight, I’ve created a poll (right margin). Please take a second and vote.

I Love Linux

Mon, 10 Aug 2009 19:24:18 +0000

$ uptime 20:20:56 up 434 days, 15:31, 2 users, load average: 2.32, 0.89, 0.53

The Volcano and the Buffer | Desktop GIS - the book

Mon, 27 Apr 2009 20:08:48 +0000

Take a look at: The Volcano and the Buffer It includes an example that uses CSV, GDAL/OGR VRT, QGIS, and fTools to figure out if I was in danger of being buried in a volcanic ash fall (not much danger but sounds dramatic).

PyQGIS Plugin Builder

Sat, 21 Feb 2009 17:26:33 +0000

One of the hurdles in developing a QGIS plugin with Python is just getting the basics down. Getting the plugin setup so it is recognized by QGIS and properly adds it’s menu and toolbar items can be a bit of a chore, especially the first time. To make the process easier, I put together a web tool to generate a plugin that can be used as a starting point. The tool creates a fully functional plugin that can be loaded in QGIS 1.

Custom Applications with QGIS

Tue, 10 Feb 2009 21:09:32 +0000

The recent release of QGIS 1.0 provides an excellent opportunity for developers looking to create standalone mapping applications with Python. I recently posted an article on creating a very simple standalone application with Python and QGIS 1.0. Much of the Python efforts thus far have been devoted to creating QGIS plugins. I think now that we have a stable API, you’ll begin to see more custom applications that meet a specialized need.

The Ink is Dry

Sun, 19 Oct 2008 20:03:35 +0000

Looks like the ink is dry on Desktop GIS and it should start shipping soon. You can get the full scoop from the Pragmatic Bookshelf. Update: It’s now shipping. See the announcement.

No Java, Please Pass The Python

Thu, 02 Oct 2008 20:10:56 +0000

After a rather long lapse, I had the occasion to write some Java code recently (mainly because it didn’t look like Howard’s PySDE was functional). I didn’t like it. Not to start a language flame war, but after using Python almost exclusively for 6 months, I found Java to be cumbersome. I kept thinking “if it were Python I could do it this way”. Sending an email from Java–frightening. From Python–simple.

Git Book

Wed, 01 Oct 2008 20:24:51 +0000

This weekend I finished reviewing Pragmatic Version Control Using Git by Travis Swicegood. If you are a git user or interested in learning about the latest in version control for your source code, check it out. The book is available in beta now.

QgisToMapServer - A Conversion Tool

Fri, 19 Sep 2008 13:17:32 +0000

QgisToMapServer converts a saved QGIS project file to a map file, ready to be served with MapServer. A binary preview version for both Mac and Windows is available now. For Linux/Unix users, the source code is available from the Git repository. QgisToMapServer is different from the plugin in QGIS. It is a standalone Python application providing the following features: Create MapServer map files from saved QGIS project files

Desktop GIS - the book - Now in Beta

Wed, 07 May 2008 16:17:39 +0000

The book is now available in beta. Excerpts from two of the chapters are available online. What’s a beta book? Well in this case it’s a lot like software—feature complete and ready for you to give it a spin. The announcement from the Pragmatic Bookshelf: The Pragmatic Bookshelf | Desktop GIS “From Google Maps to iPhone apps, geographic data and visualization is quickly becoming a standard part of life. Desktop GIS shows you how to assemble and use an Open Source GIS toolkit.

Global Warming Defeated in Alaska

Sat, 26 Apr 2008 07:02:10 +0000

Well it was a short summer here. Or perhaps we have defeated global warming. This is the view from the deck on Thursday evening: and this is the view Saturday morning: Of course nearly everyone in the country has removed their snow tires in anticipation of the upcoming May 1 deadline. As they say “Life is tough in the far north”. The good news is that now we can go directly from winter to summer…

Obligatory Eee Pc Post

Mon, 10 Mar 2008 19:49:19 +0000

Everybody who gets an Eee PC has to write about it–it’s required. I don’t really have much to add to the raft of reviews, except for one small point. I found myself wanting to print something and, based on my last experience, prepared for the ordeal of setting up a printer. I about fell out of the chair when I opened the Printer configuration and found that the Eee had already found the CUPS printer on my network and added it.

Rasters in the Database---Why Bother?

Fri, 15 Feb 2008 06:34:29 +0000

I’ve come to the conclusion that storing rasters in a database is of dubious value, particularly from a data warehouse perspective. If you manage a collection of rasters that are updated on a frequent basis, storing them in a relational database with ArcSDE quickly becomes a pain. I’m not talking about a dozen or so rasters, but rather tens of thousands. The overhead of the database and middleware just doesn’t seem to be worth it.

Wither the command line

Sun, 03 Feb 2008 11:30:36 +0000

Matthew Perry poses the question: Why is the command line a dying art?. Funny how these things go–I was thinking about posting on this same topic just the other day, although I may be repeating myself. The efficiencies of the command line cannot be overstated. I too have seen that deer in the headlights look when a GUI-only user is first exposed to a command prompt. I have also seen people spend days on a data conversion project that could easily be accomplished in hours (or less).

Beyond the RDBMS

Thu, 31 Jan 2008 19:30:14 +0000

In Beyond the RDBMS Sean references Martin’s post which in turn points us to a paper (gotta love the web in action) promoting “The End of an Architectural Era”. This paper advocates the complete rewrite (well trashing actually) of current RDBMS code in favor of specialized “engines”. It’s an interesting read with some good points until I got to this: Our current favorite example of this approach is Ruby-on-Rails.

Desktop GIS - the book

Wed, 07 Nov 2007 17:28:53 +0000

The Pragmatic Programmers have announced the upcoming Desktop GIS title.

The Leopard Limps a Bit

Sat, 03 Nov 2007 10:31:02 +0000

I use my MacBook as my “command center”, connecting to the other machines I need to work on using ssh and Nx. After a bit of tuning, I had this working nicely under Tiger. Enter Leopard. I upgraded my machine rather than a clean install — I’m in the middle of too many things to start from zero. Being cautious, I waited a few days to see what kind of issues might arise (such as the Blue Screen of Death).

Upgrading PostGIS in a Database with Large Objects

Sun, 28 Oct 2007 07:12:46 +0000

Following the instructions for a “hard” upgrade in Chapter 2. Installation of the PostGIS manual results in large objects not being restored to the database. If you create a dump using pg_dump -Fc –oids and then use the postgis_restore.pl script, the oids will be restored but not the large objects. This is not really a PostGIS issue, it can happen when dealing with any PostgreSQL database. To remedy this situation I found that the pg_dumplo utility has the answer.

The Long Road to Gutsy

Fri, 19 Oct 2007 06:40:40 +0000

I guess Ubuntu must be popular. I’m just trying to upgrade my Feisty install so I can do the upgrade to Gutsy. Looks like it’s going to take a while…

QGIS Workshop at FOSS4G2007 - A Done Deal

Mon, 24 Sep 2007 20:16:45 +0000

Well, the QGIS workshop at FOSS4G2007 is history. We had a capacity crowd and covered a lot of ground in a short 3 hours. Rumor is there are some pictures and heaven forbid, audio from the workshop floating around. Maybe they’ll surface at some point this week. I have a few LiveCDs left over and some of the coveted QGIS carabiners. If you run into me at the conference and want either, just ask.

FOSS4G2007 - Day 0 Wrapup and What's Next

Mon, 24 Sep 2007 05:27:59 +0000

Day 0 - Things are hopping in Victoria. Yesterday I helped a big group of volunteers set up 160+ PCs for the Workshops and the Labs. People filtered in all day and the process of putting faces to names was interesting. Workshops start at 0900 today (Day 1) and run till 1600, then the OSGeo Annual General Meeting begins at 1630. I imagine by the end of the day, nearly the full contingent of conference attendees will be stalking the streets of Victoria.

JUMP Start

Sat, 12 May 2007 13:22:53 +0000

This is an experience report–your mileage may vary_ I decided to give JUMP another try today. So I downloaded the latest release (1.2) and unzipped it into a directory. Looking at the JUMP Installation Guide reveals the document is written totally for Windows users. No problem, but I’m using a Mac. Looking in the bin directory there is a shell script named JUMPWorkbench-mac.sh. OK, make that executable and give it a go:

QGIS MapServer

Fri, 11 May 2007 07:17:08 +0000

Marco Hugentobler at the Institute of Cartography, ETH Zurich has announced the QGIS MapServer project. From the website: “QGIS mapserver is a server module for geographic maps. The content of vector and raster datasources (e.g. shapefiles, gml, postgis, wfs, geotiff ) is visualized according to the request parameters. The generated map image is sent back to the client over the internet.” This project is very much in the early stages, as it requires a specific development version of QGIS.

Desktop GIS - A Car With No Wheels?

Sun, 29 Apr 2007 16:59:45 +0000

Is desktop GIS software a rusty old car with no wheels? Bouncing around the blogosphere sometimes leaves you with that impression. All the excitement these days seems to center around mashups, hacks, and mapping in your web browser. It’s definitely cool stuff. A number of folks think this is the future of GIS, even when it comes to doing analysis. Part of this trend stems from a desire to deliver mapping to the masses.

Building QGIS on Feisty Fawn

Fri, 27 Apr 2007 17:13:37 +0000

Here is the process I used to quickly build (OK, but it was faster than usual) QGIS HEAD on Feisty Fawn. What’s QGIS HEAD? It’s the current development version that includes the tasty Python bindings that allow you to write both QGIS plugins and stand-alone mapping applications. With apt-get or synaptic, install the following: bison fftw3 fftw3-dev flex g++ libgeos-c1 libgeos-dev libgeos2c2a libpq-dev libpq5 libqt4-core libqt4-dev libqt4-gui libqt4-qt3support libqt4-sql libreadline5-dev libsqlite3-dev libtiff4-dev proj pyqt4-dev-tools python-qt4 python-qt4-dev python-sip4 python-sip4-dev qt4-designer qt4-dev-tools qt4-doc qt4-qtconfig sip4 sqlite3 tcl8.

Vista and Open Source

Sat, 17 Feb 2007 08:14:20 +0000

And so it begins. Chad has made a plea to Microsoft to help sort out issues with the latest World Wind release and Vista. The new security features are causing problems and I suspect that World Wind won’t be the last project to have to deal with it. So far the QGIS project has yet to get an experience report from anybody using Vista. Who knows what that will bring….

The Great Divide - User and Developer

Sat, 03 Feb 2007 11:12:30 +0000

a great divide separates the typical open source developer and user. each has differing expectations, assumptions, and priorities. the interaction between developer and user can be helpful, cordial, confrontational, or antagonistic. of course this all stems from being on opposite sides of the fence. the key to a successful relationship is communication and understanding (not exactly a new revelation). unfortunately its not possible for one developer to communicate directly with thousands of users.

Running QGIS for Windows on Linux

Wed, 10 Jan 2007 21:29:52 +0000

Why would you want to run the Windows version of QGIS on Linux? Because its there. Actually, it may be a useful way to test the Windows version without firing up the dusty old Win32 box. I did this more out of curiosity than anything else. I installed Crossover Linux (http://www.codeweavers.com/products/cxoffice) on an Ubuntu Dapper box. During the install process you are given the option to install Windows software. Of course QGIS isn’t in the list of supported software, but there is an option to install Unsupported Software.

Top Ten Open Source GIS Predictions for 2007

Wed, 20 Dec 2006 17:15:11 +0000

I remember growing up and reading predictions for the new year developed by some prognosticator, supposedly in the know. Of course most of the time it was all wrong, but often made for interesting reading. With that in mind, here are my top 10 predictions for Open Source GIS (OS GIS) for 2007. Top Ten OS GIS Predictions (in no particular order) OSGeo will be a synergetic force, fostering new cooperation and collaboration between projects.

ArcGIS Image Server

Fri, 15 Dec 2006 06:34:39 +0000

I was interested to read that ArcGIS Image Server is now available. Now I admit that I haven’t had any advanced information about the product (has anybody?) but was disappointed to find that its only supported on Windows servers. Disappointed but not surprised. I was hoping for a more open API (specifically something other than ArcObjects and/or .Net) and the ability to use image server on Linux/Unix.

Configuring Lighttpd with FastCGI for MapServer

Tue, 17 Oct 2006 18:31:47 +0000

In an effort to obtain a faster and lightweight solution, I decided to use Lighttpd (AKA Lighty) with FastCGI to power MapServer. Snooping around the MapServer site yielded no clues on how to configure Lighty. It turns out to be fairly simple. Here is the Lighttpd configuration: fastcgi.server = ( "/maps" = ( "localhost" = ( "socket" = "/tmp/mapserver-fastcgi.socket", "check-local" = "disable", "bin-path" = "/usr/lib/cgi-bin/mapserv", "min-procs" = 1, "max-procs" = 6, "

Oblique Speak in the Technical Realm

Mon, 18 Sep 2006 16:06:42 +0000

It amazes me how people fail to communicate when speaking about technical matters. I’m sure you have heard this refrain: “My computer doesn’t work” or perhaps “Program XYZ blows up”. Ok, in the general sense there is some information being conveyed here. Often times the speaker is not merely providing a fact but asking for help in a very oblique manner. Before you think I’m picking on the poor newcomer, I’m not.

Diminished Expectations

Sat, 26 Aug 2006 19:57:08 +0000

I’ve had to lower my expectations of the Open Source GIS user community. Now that I have your attention, I’ll explain. The OSGIS user community by and large is composed of a great bunch of folks. Its the few that have soured my outlook a bit. I repeatedly see posts to mailing lists blasting one application or the other (usually not to the project’s own list but another). The software stinks, doesn’t work right, the developers are stupid, its not as good as X, Y, or Z, and so forth.

Making Open Source GIS Easier

Wed, 12 Jul 2006 22:14:23 +0000

How can we make getting started in Open Source GIS easier? To begin with, it needs to be easier to Discover Install Use Discovery This is probably the least of the problems, but you would be surprised how many people “stumble” on OS GIS each day. Things are improving as more exposure is gained through books, blogs, conferences, and the media. The more we talk about it, the more well known it becomes.

Brittle Systems

Sat, 29 Apr 2006 10:51:57 +0000

Lets face it, GIS systems are complicated. Typically there are multiple servers and applications that make up a “system”. Each of these represent a potential point of failure, thus creating a brittle system. Brittle systems break. The definition of the word brittle is: Brittle: Solid, but liable to break or shatter In other words, we can design solid systems that serve us well, but they can be brittle. We can push on them a bit and they perform well, but push too hard and the whole thing shatters.

GIS Data is an Illicit Drug

Wed, 29 Mar 2006 20:02:47 +0000

GIS data is like an illicit drug. You can’t control it. It travels in secret and hides in the dark alleys of your organization. Its effect spreads and enslaves those that use it. In the end it can lead to ruin. Well maybe its not that bad but organizing and managing your GIS data is difficult. If you need to maintain canonical datasets, the spread of “temporary” and/or “working” copies is your enemy.

Hail the Command Line

Fri, 24 Feb 2006 00:16:36 +0000

In this day of GUI GIS, sometimes you can’t beat the good old command line for getting a job done, regardless of whether you use Linux/Unix, Mac OS X, or Windows. This may sound strange coming from someone heavily invested in a GUI project but its true. Case in point - I recently needed to create two seamless regional layers from over 100 individual shapefiles. The source shapefiles were stored in individual subdirectories two levels deep.

Free Support for Open Source GIS

Tue, 07 Feb 2006 21:29:24 +0000

One of the often overlooked support mechanisms for Open Source GIS applications is Internet Relay chat, better known as IRC. Many OS GIS projects maintain an IRC presence. Often times you will find the project developers hanging out on the channel and willing to answer questions (more about that in a bit). Speaking personally, the Quantum GIS project has used IRC for project coordination, communication, and user support for several years.

Should MapServer join OSGeo?

Mon, 06 Feb 2006 13:56:18 +0000

The MapServer Technical Steering Committee today approved an RFC that calls for MapServer to join the newly formed Open Source Geospatial Foundation. A poll has been put up on the MapServer site (login required) to collect the responses from the community. So far the vote is unanimously in favor of joining, although the poll has only been open for about an hour. Some thought it interesting that MapServer didn’t join immediately, given it was at the center of the failed MapServer Foundation attempt at the end of last year.

Open Source Geospatial Foundation Meeting - Review

Sat, 04 Feb 2006 15:57:27 +0000

This is an unofficial recap of the OSGF meeting, based on my recollections having spent 10 hours on IRC and the phone. I’m sure the foundation will release an official version of the day’s events, so take my comments with a grain of salt. As I stated in an earlier post, the name was chosen early on and without an excessive amount of debate. OSGF rolls off the tongue rather easily and has a nice ring to it.

Open Source Geospatial Foundation

Sat, 04 Feb 2006 08:00:27 +0000

Well, I have been participating in the “GeoFoundation” Meeting since 5:30 am local time this morning. We’re two hours into the meeting and so far a name for the foundation has been agreed upon: Open Source Geospatial Foundation. The domain osgeo.org has been registered. I suppose most folks will refer to it as OSGF from this point on, although the term OsGeo was also mentioned in the discussions. I was concerned that the name of the foundation would become a major stumbling block in making progress during the meeting, however the groundwork and informal polll seems to have paid off in that regard.

Dual Booting the Powerbook

Sat, 28 Jan 2006 19:33:28 +0000

I use Linux and OS X as my primary operating systems. Lately I have been using the Powerbook exclusively with ssh or FreeNx to work on the Linux machines on the network. I started off to simply repartition my Powerbook and then reinstall OS X and put Ubuntu on the new partition. That was two days ago. Things are pretty much back to normal now. I have a dual boot system that I can take with me and run my favorite GIS software on both platforms as needed.

Spatial Galaxy

Fri, 25 Nov 2005 09:21:14 +0000

This site aims to bring out some of the latest and sometimes not-so-greatest happenings in the GIS world. We’ll focus to large extent on Open Source software but hopefully mix it up to keep things interesting. We’ll explore things from the new and exciting to the dull and mundane. There are a lot of GIS/Spatial sites out there. Hopefully we can provide some content of interest and you will add this one to those you visit frequently.