Covered Topics:
- US Census Bureau Using QGIS
- Map Composer Templzates
- QGIS 3.0 Release
- Using Time Manager to Animate Commercial Shipping Data
- Using High Rsolution Screens in Windows
- Auto Saver
- Basemaps
- Default Fields with GeoPackage Data
The February meeting was held at Interim CDA. Thanks again for their generous use of their conference room.
- Paul showed how the Census Bureau is using customized versions of QGIS known as GUPS for boundary and address data update by local governments in preparation for the 2020 US Census.
- Video hosed by the San Diego Association of Governments.
- Peter and Evan explored templates for Print Composer.
- The computer used for demonstration was running QGIS v2.18.14.
- From a configured map composition in the Print Composer window, save as template.
- Positioning of the various objects in Print Composer is saved in the template.
- There is a Print Composer folder that is used by default: .qgis2/composer_templates
- Within one project you can’t use a template to save a given map extent/scale.
- Alternatively, bookmarks are available in the main QGIS window. They are saved globally to your computer, available from all QGIS documents.
- Evan mentioned that QGIS 3.0 will be released in 10 days.
- There are still many plugins that people rely on missing for version 3.
- Selective masking is a promising new feature.
- Stu demonstrated an interesting technique using Time Manager to animate commercial marine vessel movement in the Salish Sea with tails trailing behind the points as they move across the map.
- Stu used two techniques from Nyall Dawson:
- Label halos
- QGIS live layer effects
- It doesn’t work in Map Composer.
- It uses the Draw Effects settings.
- Commercial marine vessel traffic data from MarineCadaster.gov.
- Data available from 2009 to 2014.
- Created tails for his points using Trajectory animations with fadeout effects from Anita Grazer.
- Starts with a large magenta dot that fades out over time and a small green dot that fades in over time.
- Sets a data defined overide on the fill, and size attributes for the symbol.
- Copied the code provided on Anita Grazer’s blog.
- For more information look at scale_exp usage in the Expression Builder.
- The layer being symbolized has to have a text field in it that conforms to the time format string.
- Stan uses Sony Movie Studio Platinum to assemble the the PNG files produced by Time Manager into a video.
- Stu used two techniques from Nyall Dawson:
- Joel shared a tip to get QGIS to work right with high resolution screens with Windows 10.
- It turns out he found an answer that Stu had provided in Stack Exchange.
- Stu said this works not just with QGIS but with any software in Windows.
-
Evan shared a tip to install and use the autoSaver plugin to keep from losing work if you have trouble with QGIS crashing as it will save your document on a periodic basis.
- Stu shared a fast way to add tiled basemaps.
- In the Browser Panel select TileServer (XYZ) - add Connections.
- Evan said that turning on the Use Native Render checkbox in the Quick Map Services plugin may accomplish the same thing, by enabling the improved tile indexing code.
- Joel explained how to configuring default field values when adding features using data in GeoPackage format.
- Works with lines, points, polygons, and attributes only with tables.
- Similar to building “domains” in ArcMap.
- Attribute table has a type field and an attribute_schema.
- attribute_schema is a text field with JSON schema code in it.
- type field is only in the geometry layers.
- Fields have default values, etc defined in the Layer Properties, Fields tab, Edit widget.
- Fields tab: Python Init Function and Function Name
- Uses the JSON schema to populate the fields.
- Attribute table has a type field and an attribute_schema.
- To share this you need to include: the GeoPackage, the QGIS file, and the scripts, all in the correct directories.
If anyone has corrections or additions they would like to make to these notes please let Paul McCombs know, or submit a pull request on github