Comment by tonyarkles
3 days ago
Been using QGIS for about 6 years now for doing manual data analysis, as well as GDAL and Spatialite in C++ for creating/saving datasets and geopandas, Shapely, pyproj, etc for automated analysis.
QGIS is an odd duck. Part of the complexity of using it is the fundamental complexity of GIS software. There’s way more background info that I didn’t know (what do you mean a latitude and longitude doesn’t mean anything without a bunch more info?!) that’s necessary to use it effectively. All of the excellent UI in the world won’t save you if you’re not using the right coordinate system.
On the other hand… yeah, it definitely could use some love. I consider myself in roughly the amateur power user category. I don’t use it every day, but when I do fire it up once or twice a month I’m doing some heavy data analysis with it. Every time I do that I end up tripping over three or four things that seem like they should be obvious to do but aren’t. And man oh man… if there was a single bug I would love to fix: highlighted points, whether selected through the selection UI or through the data table… should always have a higher Z-order than the other points around them. The fact that you can select a bunch of points and not see them highlighted… so frustrating. You can go in and change the symbology to fix that in a number of ways but dammit it should work right out of the box. /rant
Hard agree on it being odd in both GIS ways and QGIS ways. I just started a new job that pays for ArcGIS Pro and it’s wild how something that seemed intuitive to find on QGIS is buried under menus on Arc Pro, but conversely I’ve definitely seen things that I’m like “that was almost too easy why doesn’t QGIS have this”. And then you have the oddities of GIS
> what do you mean a latitude and longitude doesn’t mean anything without a bunch more info?!
Is the more info just the coordinate system like WGS84, or am I missing something else?
There are many different coordinate systems that aren’t WGS84, and there are different epochs associated with them as well. Some of the use latitude and longitude, some of them use easting/northing, etc.
The worst part is that if you don’t get it exactly right, you’ll still get answers that look right but are shifted by maybe 1-3m. As an example, we had a field team out with a Trimble survey stick with RTK (nominal accuracy 1-2cm) that they were using to cross-check data from our aerial survey platform. We had laid out a bunch of targets on the ground, which they surveyed the corners for. Most of the time there was a fantastic match between the aerial survey data and the ground truth data, but occasionally there was a pretty large offset. As I discovered WAY too late, exactly one of the cellphones that ran the Trimble app had its coordinate system set to one of the Canadian CSRS frames instead of WGS84: https://natural-resources.canada.ca/science-data/science-res...
Edit: naturally, they just handed me the coordinates in a CSV file that they’d captured. The Trimble app + whatever data collection app didn’t actually record the reference frame.