PyQGIS Programmer’s Guide

Posted by Tyler Mitchell on March 03, 2014
Book review / Comments Off

I must confess, in all the years I’ve used QGIS I never did much of anything with the Python-QGIS API.  But now I can learn it

easily, and you can too, with the latest book from Locate Press:

PyQGIS Programmer’s Guide – Extending QGIS 2.x with Python

Written by Gary Sherman, the father of QGIS, you know it won’t be fluff!


  1. Introduction
  2. Python Basics
  3. Setting Up Your Development Tools
  4. The QGIS/Python Ecosystem
  5. Navigating the QGIS API
  6. Using the Console
  7. Running Scripts
  8. Tips and Techniques
  9. Extending the API
  10. Writing Plugins
  11. Creating a Development Workflow
  12. Writing a Standalone Application
  13. Answers to Exercises
  14. Appendix A: Installing Software
  15. Appendix B: Code Listings
  16. Appendix C: Porting Scripts to 2.0


Check out FOSS4G event in Portland

Posted by Tyler Mitchell on February 11, 2014
Uncategorized / Comments Off

Though it’s been years since I attended a FOSS4G event, it’s getting temptingly closer to home (geographically speaking). I know several good folks down in Portland and Oregon, so can rest assured that recommending you to check it out is a safe bet.  I’m sure it will be an all-you-can-eat smorg of geospatial software goodness!


Training: extending QGIS, intro too

Posted by Tyler Mitchell on December 28, 2013
Uncategorized / Comments Off
If I needed QGIS beginner or advanced training, I’d try to take it from the founder of QGIS. Gary Sherman is advertising his 2014 courses on
Training from GeoApt LLC

We are currently organizing courses for the upcoming year:

If you are interested in either of these offerings, please register and we will send you details as to venue and dates once they are firmed up.

GDAL/OGR Book Released!

Posted by Tyler Mitchell on November 02, 2013
Book review / Comments Off

I’m happy to announced that Locate Press has just released a “first look” preview edition of my latest book…

Geospatial Power Tools - Open Source GDAL / OGR Command Line Utilities

Geospatial Power Tools - coverIt’s a 310 page collection of all the GDAL/OGR command utility documentation, written by the GDAL Developers.  Included are also about 100 pages of new content that shows more examples of how to use the various commands to do specific tasks.  This will help those who may not know what command to use, but who know what task they want to do – i.e. convert an image, mosaic images, query a WFS, etc.

From discussions I had over the past few years, it seemed many people needed this book or knew a colleague who could use it.  I know when I worked in forestry GIS and used these tools it was exciting, but my colleagues didn’t know about them and there wasn’t much available to help fill that gap.  I hope this book effort does help.

This is a PDF version so far, but expect a Kindle and paperback version around the end of the year!

20% off sale this weekend
coupon code “firstlook”!

2 Dashboard examples – Devops and more

Posted by Tyler Mitchell on September 20, 2013
Uncategorized / Comments Off

I came across a couple interesting packages recently for both system and app monitoring scenarios.


Their “Beautiful Dashboards” slogan says it all – they have a free version of their DevOps Dashboard system for monitoring up to 3 servers.  Among lots of cool stuff, I especially like how they show historic ranges in the background of charts, and flag anomalies visibly.

DataWatch / Panopticon

I met some of the DataWatch team at the recent Data Viz Summit and was impressed with their tutorial on using their dashboard building tools.  It all looked good and was easy to build and use – also the ability to drill-down was quite powerful as was their ability to attach to streams and perform playback.

Tons of demos at

QGIS Training Manual and Locate Press changes

Posted by Tyler Mitchell on June 04, 2013
Uncategorized / Comments Off

Today’s an exciting day on several accounts…

First, it’s the day that Locate Press’s second title is now starting to become available through Amazon!  There are several titles in the works but this one made it past the post first.

This relates also to my second item…  I’ve stepped back from Locate Press over the past month to hand the leadership over to Gary Sherman.  This is really good news for all our readers and future authors, because he will have more time than I did to keep things moving forward.

Personally, my day job is demanding enough for me at the moment and I knew it wasn’t going to get any easier, so finding a replacement to take over the company was a no-brainer.  Gary’s been involved with Locate Press from the very beginning and knows the toolchain, editorial processes and publishing paradigm just as well as I ever did.  In fact, he single handedly put the QGIS Training Manual into production, which was inspiring to watch from the sidelines.

I’m still around and helping where needed, but am focused on my continuing work with Actian Corp which is growing and innovating in some interesting ways – it’s a great company to being working with and I’ll share more as things progress there.

By the way, with this transition, it’s a great time to pitch your new geospatial book ideas to Gary – drop him a note!

Thanks for all the support I received when launching Locate Press!!

Ecstatically Hyperlocal Communication Matrix – aka Coffee House

Posted by Tyler Mitchell on April 18, 2013
Uncategorized / Comments Off

Jack into the ‘net -make an impact and realise your full potential!
Taken from future advert for the first Matrix implant computing system.

By metacortex on

Don’t sign me up…

I really enjoy technology that allows me to do work from a remote home office, but outside of work unless the technology enables face-to-face time and with people geographically near to me then my time may be best spent elsewhere.  Having children helps keep it real for me.  My filter operates on the premise that unless something I’m doing online is going to benefit my work/career, my family, my community, or teach me something useful within those spheres – then it’s not high priority.

Stay with me, this isn’t just a rant about disconnectness or a deadbeat Internet obsessed parent!  This potentially applies to you, your business network and how you come up with new ideas.

Social apps leave me cold.  I guess if they’re called social apps I can’t fault them for focusing on solving social “problems” such as “How to find your friends on Friday night!” or answering important life questions like “should I eat here?”  Now we’re able to find “deals” locally and much much more with all this hyperlocal app mumbo jumbo.  But how did we ever survive without these precious tools?  I dare say we had to talk with friends, family and neighbours to get recommendations or phone them to ask what they’re up to next week.

All the work-related benefits of Internet/social apps/LBS technology aside, consider how information technology can easily push us toward isolation from others around us.  On the surface it doesn’t seem to be a bad thing – with 10 minutes noticed I can hang out online with more geo-geeks than I can ever muster up within a 400km radius from my home office.  Seriously.

But when it comes to connecting with my neighbour, our city council or even local businesses, it’s a complete and utter fail.  Granted, I don’t live in the largest municipality, but the impact is similar in large centres too.  You can occasionally find some new local shop or service you didn’t know was just around the corner, but more often than not you find one that is across town or out of town instead.  As we travel to these non-local sites we continue the isolation from our “real” local communities and local business networks.

If the technology is helping isolate us, how do we bring it back around?  Egads!  It gets kinda messy to be liberated from this Matrix machine sometimes, but there are some time-tested models for rehabilitation that you might consider.  Here are two…

In a previous post (Open Gov/Data Needs Collaborative Common Spaces) – I proposed that we need to get data providers into the same rooms as those who are users or, better yet, those who best add value to the data.  Rubbing shoulders, face-to-face, sharing problems and solutions across domains and disciplines is key.  We don’t always know what the outcome will be, but the more isolated these stakeholders and providers are, the more insular the outcome.  Guaranteed.  I was pointing to the co-working model as one way to help make that happen – though enabling public servants to hang out in more accessible locations may be the largest barrier to that idea!

Steven Johnson touches on a similar vein in his talk on where good ideas come from.  Hint: it’s not from reviewing the results of a multi-year stakeholder survey.  Nor is it from mining mailing lists or user groups dedicated to a particular topic.  His conclusion is similar to mine, using the coffee house as an example of the kind of unstructured communication that leads to breakthroughs.  Now we are way beyond metaphors here, we’re talking real, meaningful and messy ways of bringing people together to serendipitously meet, chat and share.  That could be around the boardroom table once a week when you bring in disparate team members, but even better if you can be rubbing shoulders with others in a non-exclusive environment.

What does that look like?

I have some vague ideas – co-working space, coffee shop, impromptu customer visits, hackfests, heck even the water cooler! – but I think we’re still early in defining what these look like and how to best engage at a more meaningful level.  Ironically, I do believe that much of the answer lies in (pre-Internet era) history, so asking relatives that are not as online connected may reveal some interesting results.

However, I do believe that the first step in truly coming to grips with the reality of techno-fueled isolation is to admit there is a need to “bring ourselves back together” in a meaningful way.  It’s early days, but mark my words we’ll have a whole industry devoted to helping people get “unplugged” and we’ll see friends and colleagues disappear from online while they reclaim their local relationships.  I don’t think it needs to be that dramatic but is worthy of some consideration to find an effective balance and to check that our pulses are not timed with our router packet traffic.

We’ll know there has been progress when hyperlocal starts to refer to relationships between people and not our relationship with applied technology.  Likewise, we could benefit by reclaiming the definition of communication as a conversation between two people.  And the time is now, not after Skynet becomes sentient or the Matrix materialises… without our knowing.

GeoServer Beginner’s Guide

Posted by Tyler Mitchell on April 18, 2013
Book review / Comments Off

This past year I started using GeoServer more than I did before.  Actian is using it to demonstrate the capabilities of the Ingres 10S database sitting behind it.  So I was glad to see that there was a new book out on the topic, by Stefano Iacovella and Brian Youngblood.

It was very readable and went faster than I thought it would (maybe it would have been longer if I didn’t skip a few exercises ;-) ).  The book opens with the standard GIS Fundamentals but by the end of it you can be hacking XML and hitting the REST interface.

A few highlights to consider… Those who struggle with getting started with Tomcat on Linux will appreciate the chapter on installation.  Likewise there is a chapter pointing out how to better secure everything before going into production.

The book is packed full of screenshots and graphics, making it very easy to follow along.  The authors also did a great job making it readable and accessible.  I would recommend it for anyone who is a first time GeoServer user.  Check it out here.


Open Gov/Data Needs Collaborative Common Spaces

Posted by Tyler Mitchell on February 25, 2013
Uncategorized / Comments Off

When innovation is sought after, for example in the government open data initiatives, it becomes even more important to have effective connection with people in the trenches.

I propose the use of collaborative meeting spaces, a sort of Demilitarized Zone for government and constituents to connect – physical places where they can meet together, and not just so they can meet face-to-face, but to implement an innovative (new?) way of making spontaneous collaboration happen

Read my full article on

Desktop + Processing Server = GeoShangri-La

Posted by Tyler Mitchell on February 19, 2013
Uncategorized / 4 Comments

Those who know me are likely sick of my retelling of stories about my observations on the impact of migrating away from command line GIS (circa ArcInfo Workstation) to the typical desktop GIS with graphical user interfaces. More often than not, however, my desire for server-side scripting is now done within spatial databases (Ingres and Postgres/PostGIS databases being the two I recommend the most).  The interface between the GIS client and the server is still ripe for innovation however.

While some desktop applications can leverage server-side processes, instead of pulling it all down to the client, I have seen it less in-the-wild than I have the traditional client-side approach.  I’m hopeful that with products like ArcGIS Server, GeoServer or even GIS Cloud, PyWPS, deegree, 52North, Zoo, etc. much of that work will finally be put where it belongs.

Enter the Web Processing Service (WPS) to help glue it all together.  A couple years back I barely knew this existed, but now that it is easy to enable this on GeoServer, it’s starting to draw my attention more and more.  However, I can’t help but think that lack of client support is hampering the adoption of a WPS-based workflow.  When I saw there was a WPS plugin for QGIS then I really started paying attention!

Here’s why…

Imagine having layers loaded, say, through a WFS.  So you’re just drawing some features, selecting a few and then sending off a request to the server to process a buffer or to do a clip function.  Behind the scenes, QGIS would send just the select shape of interest, tell the server what process to run (along with some other parameters) and return the result to your map view.  Only a few local temporary files and all is done in one spot and kept clean.

Too good to be true?  You be the judge and let me know :)

p.s. The ultimate end game for me here is to have my Ingres spatial db serving up customer data via WFS, with options to process the data with GeoServer WPS.  I’ve tested against other platforms with more success, but I’ve only gotten halfway there with GeoServer.  If you’ve done QGIS with WPS plugin against a GeoServer WPS instance, I’d like to hear from you (twitter: spatialguru).  I can get it to create a grid, for example, but I can’t get the client to send data to the server and get a result.

Tags: , , , ,