North River Geographic Systems Inc

Spatial Problem Solving

rjhale

QGIS Processing: History

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If you’re anything like me (hopefully you aren’t) you’ll do something and immediately wished you hadn’t closed the processing window. Clip, simplify, select by location……

So in this case I had a call about contouring a Digital Elevation Model. Contours are easy. I ran them at 10…or maybe 20.

QGIS and DEM

I decided to clip them with the county boundary since the DEM extends outside of the county into the neighboring counties and states.

QGIS and Clipped DEM

So the question is now “WHAT DID YOU DO”. You get up. You come back. Cat jumps in your lap. Your Mom calls. QGIS keeps a history of your processing commands. If you look at the processing toolbox you’ll see a small clock.

Click it and another windows opens

Here is the cool thing. You click any of the commands and you’ll be taken back to your original QGIS Processing menu. So if I can contours and don’t like them at 20 foot intervals? Go back and check the history, double click,  and change it to 10 and run it again. You like python? You have what you need to know and you can run that from the python console. I made one small change and dumped it to a shape this time vs a memory layer:

So if you do forget a tool setting in the processing tools after you closed it – just run it again by looking at your history for the processing toolbox.

 

QGIS North America Meeting 2020

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The QGIS US Users Group & partners in North America are proud to announce the QGIS North America 2020 virtual conference to be held on Friday, July 17, 2020 (and Friday, July 24th if needed). We offer this meeting as a way to share our ideas and skills when so many in-person meetings cannot safely happen. We recognize that while we are all separated, we have the opportunity to include people in a greater diversity in locations and economic situations since travel and registration costs are not necessary. We invite participation from all over the globe, but presentation times will focus on the North American audience.

The cost to attend will be free, and we would like to suggest attendees make a donation to support QGIS at https://qgis.org/en/site/getinvolved/donations.html

Call for Participation

The organizers of the QGIS North America 2020 virtual conference would like to solicit proposals for participation in this conference to be held online on Friday, July 17th (and potentially Friday, July 24th, with sufficient interest) in the form of talks, workshops, birds-of-a-feather networking sessions, and ideas for other session. Sessions can focus on any aspect of QGIS and we particularly encourage talks about applications of the software, software and plugin development, and discussions of transitioning to using QGIS software from other tools. Proposals for sessions should be submitted online via our Google Form: https://docs.google.com/forms/d/e/1FAIpQLScXVbO58aMZMmHo1mT5QEpF7uPki79e8PCyRJ9tBna_2IcAvw/viewform?usp=sf_link

Proposals for talks, birds-of-a-feather networking sessions, and ideas for other session require

  • Contact information for the presenter
  • Title
  • Description or abstract

Proposals for workshops requires

  • Contact information for the presenter
  • Title
  • Description or abstract
  • Length (in hours) of the workshop
  • Software requirements
  • A list of people who can potentially act as helpers (does not need to be finalized at the time of submission)

The deadline for submission is Friday, June 12, 2020.

Fed Geo Day 2020 June 11th and 12th 2020

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You know what I was going to do next week? Going to Washington DC and Teach a QGIS class.

You know what I’m doing now – Sitting in my house and teaching a class at Fed Geo Day on June 12th 2020

So what is Fed Geo Day:

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For decades open source software has been at the forefront of innovation in data collection, analysis, and visualization. Today, open source geospatial software has evolved into an “open ecosystem” of software, communities, and companies that enable field data collection and advanced visualization and lead the way in drone, lidar, IOT, and satellite imagery collection and analysis.

When open source software is combined with open standards for interoperability, government agencies have the most scalable, stable, secure and cost effective tools available to support activities including:

  • Empowering disadvantaged communities with limited funding
  • Enabling real-time data analysis at planetary scale
  • Optimizing release schedules for constituent facing tools

Join us for this one day conference in the heart of Washington DC. The morning plenaries will share how open source geospatial tools have become a critical part of operations within multiple federal agencies. The afternoon break out sessions will tackle technical and management solution use cases.

  • $20 dollars gets you into the conference
  • $20 dollars gets you into the QGIS Class. There are a lot of training options beyond the Introduction to QGIS class.

Attend! Support Open Source in the Federal Space!

Pesky Work Anniversary Again

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You’d think I’d remember – but I don’t. Linkedin reminded me though…..”Hey you’ve been in business X years”. Was it 12? 14? 11? I can’t remember.

I always try to write something just to remind myself of “where I am” in life. This year I find it exceptionally difficult to write anything without going back and doing a complete edit. So I decided this was the final Edit.

One February 12th I drove to Charlottesville VA for a quick speaking engagement at a conference. Went out to eat with a group. Had some excellent conversation. I finished up the talk and left the next day and headed back. Remarkable? No. What is remarkable is that may actually be the LAST IN-PERSON CONFERENCE I have this year. IN FACT – I said this weekend “Had I known I would have stayed an extra day or done something to enjoy some place greater than 5 miles from my house.

Every year I dig myself deeper into Open Source and deeper into data. I look back at me in 1992 and GIS was this fun thing to make maps with. I haven’t made a map as a final product in years but I’ve churned through a lot of data. This year things were looking up more than other years and I’ve been toying with “Maybe put someone on contract to help” which would give me more time for canoeing and what not.

Well…..Pandemic. I’ll be the first to admit that I didn’t grasp the initial idea of a pandemic when it started. I’ve been through several: AIDS, Swine Flu, and watched in horror at Ebola. None of those actually hit home or caused me any personal discomfort. AIDS Should have. Swine Flu seemed to have came and went quickly. Ebola was one of those things you watched as a GIS person with some morbid fascination.

…But Covid 19.

So I watched work die. Finally 8 (are we at 10?)  weeks in things are starting to loosen up as people are calling and today I at least do an estimate.With work starting to look probably again my mental attitude has gotten better.

….but…My Stupid Home Town. YELLOW ISN’T GOOD

 

It’s a somber work anniversary. Four weeks into Quarantine I had decided “this might be it”. Eight weeks in and “What could I do if I wasn’t doing this…”. There are parts to this job I love and parts I hate – but I do love maps. I do love data. I do love the Community I’ve wedged myself into.

With that – I have no great end to this post.

Good People – Stay Safe!

 

 

 

 

 

 

 

 

 

 

 

 

QGIS and Editing: Widgets

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I’ve been getting more questions lately on QGIS from all over the place. A pandemic will apparently: cause you to experiment with software, do some weird things with existing software, or call me up and ask “How do you work from home this sucks”. So one question started out with “I need to edit some data for the team and I need to keep up with what I edited and no it’s not in a database”.

In my perfect world you edit against postgresql/postgis and I set up some triggers to at the very least record who and when and possibly X and Y (or Y and X).  If you’re stuck with a shapefile, spatialite database, or Geopackage what can you do? So you have these things called widgets in QGIS……

So we’re going to play with a geopackage because that gives me some talking points for the next blog post. The ruggedly handsome client (me) has shoved some data into a geopackage. Geopackage has no login so I’m going to add my data to QGIS and do the following things:

  • Add two fields called ‘edituser’ and ‘editdate’
  • Set up two widgets in your QGIS Session.

If you right click on a data layer and go to properties you can set up a widget for your fields (under Attribute Forms). A widget can be a drop down list (something like a domain on a subtype for you over in ESRI Land).

So for the edituser field I will pick a simple text edit widget with a default value of ‘rjhale’ (At the Bottom of the menu).

The editdate field gets slightly more complicated. For that one I reach into the myriad of QGIS functions and pull out the $now. So I apply it as a default (and check that I want it to update if I move the line):

 

So moving forward I can at least keep up with “who” edited and “when”.

That’s possible the simplest use case of a widget you can have. What if you wanted to update the length of a line automatically? The QGIS Function is $length and you could apply that as a default to a widget on a field and have it calculate the length.

The big take away on this is you can do some very simple things to help your editing life. Two widgets with default values and you can keep up with what you’ve done (or maybe a co-worker) in an attempt to combine the data back together at a later time. A giant shoutout to Spatial Thoughts as I start to dive into more widget magic over the next bit.

 

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