QGIS tutorial torture track

 I tried to follow the QGIS Forestry tutorial (link below) on a couple Raspberry Pi's (would have liked to use only one but meh). I got up to vector-to-polygon and then stalled on the first day hands-on. In 2 weeks there's a QGIS conference in town I'm attending; consider this my study hall.

Previously: jspath55.blogspot.com/2023/09/tiling-for-geo-map-referencing-in-qgis.html

Wherein I list the QGIS versions within reach. Odd to have this many flavors, so let's do the taste test, starting with the Pi with the newest version, running on OpenSUSE. 

The OS is missing something in the Perl layer which results in error messages and missing menus. Until I can track them down or they reappear with an unrelated app upgrade.

Tutorial link:

https://docs.qgis.org/3.28/en/docs/training_manual/forestry/index.html

The learning here is use the filter (search) field to enter the coordinate reference system (the other CRS, not the can't remember stuff one) with numbers. I missed one of the transformations as the version I used had slightly different field text.

Geo-referencing was easy until I misread something, throwing off the mark. Easily seen by the result, and I skipped to the next lesson by keying in the exact values instead of trying the visual drop the claw-grab protocol.

Very nice to have the answers in the margins, so to speak.

The skewed first version:

Maxwell Smart voice: "missed it by that much."

Gnu Imp

Sigh. Crashed on tutorial section trying to select by color.

Bang, Zoom, to the Moon, or as my Brit friends might say, "Cloud-cuckoo-land."

12:33:55

12:34:01

Fortunately, only the user session/window manager died, not the whole OS as it might look.

Switched over to another PI running Rasbian (but QGIS 3.10) that had Gnu Imp which worked, to a fault.

Gnu Imp - Lower Left of Map

More results in the green goo.

Not the ideal output the tutorial has, but the steps are workable. Later attempts to move to polygonal spaces failed as the Raspbian was missing parts, or I cannot find them yet, and the OpenSUSE needs the python hooks re-hooked to shape up the shape files.

SQL FUN

Something was in the wrong mode.

ERROR 1: sqlite3_exec(DROP TRIGGER rtree_states_provinces_geom_update3) failed: attempt to write a readonly database

ERROR 1: sqlite3_exec(CREATE TRIGGER "rtree_disputed_borders_geom_update3" AFTER UPDATE ON "disputed_borders" WHEN OLD."fid" != NEW."fid" AND (NEW."geom" NOTNULL AND NOT ST_IsEmpty(NEW."geom")) BEGIN DELETE FROM "rtree_disputed_borders_geom" WHERE id = OLD."fid"; INSERT OR REPLACE INTO "rtree_disputed_borders_geom" VALUES (NEW."fid",ST_MinX(NEW."geom"), ST_MaxX(NEW."geom"),ST_MinY(NEW."geom"), ST_MaxY(NEW."geom")); END) failed: trigger "rtree_disputed_borders_geom_update3" already exists

FILE TIFFing

tutorial-pi400/rautjarvi_green_georef.tif: TIFF image data, little-endian, direntries=29, height=4561, bps=362, compression=none, PhotometricIntepretation=RGB, name=U:\Dropbox\GISMOOD_KESKUS_prj2014\0-13004-002-Simosol-online_gis_materials\1-mets\303\244materiaalit\0-mets\303\244materiaalit\ex1-map digi, description=Groovy Green Goo, orientation=upper-left, width=2014

C.R.S.

"Multiple operations are possible for converting coordinates between these two Coordinate Reference Systems. Please select the appropriate conversion operation, given the desired area of use, origins of your data, and any other constraints which may alter the "fit for purpose" for particular transformation operations."

"An alternative, ballpark-only transform was used when transforming coordinates between EPSG:2392 - KKJ / Finland zone 2 and EPSG:3067 - ETRS89 / TM35FIN(E,N). The results may not match those obtained by using the preferred operation:

Possibly an incorrect choice of operation was made for transformations between these reference systems. Check the Project Properties and ensure that the selected transform operations are applicable over the whole extent of the current project."