spatialthoughts / qgis-tutorials

Source files for sphinx-based website

http://www.qgistutorials.com

Apache License 2.0

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Advanced Raster Analysis (QGIS3) — QGIS Tutorials and Tips #180

Closed utterances-bot closed 3 months ago

utterances-bot commented 3 months ago

Advanced Raster Analysis (QGIS3) — QGIS Tutorials and Tips

https://www.qgistutorials.com/en/docs/3/advanced_raster_analysis.html

manaswi1993 commented 3 months ago

Hi, I am trying to use the "Raster calculator" algorithm (Steps 14-17 above), but getting the following error: "Error occurred while performing calculation."

I am using QGIS 3.34.8-Prizren LTR, and the "Raster calculator" dialog box looks different from the dialog box screenshot used in the page above.

I am wondering what the problem is.

I am using "SA_NLC_2018_Clipped" as the "Input Layer", the expression as you have put above, the project CRS and all other layer CRS is EPSG:4326.

spatialthoughts commented 3 months ago

Thanks. This has been updated in https://github.com/spatialthoughts/qgis-tutorials/pull/182.

Dyounglecturer commented 3 weeks ago

Thanks for the job well done. However, When I get to the last stage, I noticed my layer styling changed from 0, 1, 2, and 6 other color number. What could have caused this? Or was it because the time difference has long and new attributes have been added to the map automatically? Any advice on what to do will be appreciated

spatialthoughts commented 2 weeks ago

@Dyounglecturer The result should only have 0,1 and 2. Try again with the datasets linked from the tutorial (also linked below).

SA_NLC_2018_ALBERS_CALC.tif

SA_NLC_2014_2018_CLASS_CHANGE_ALBERS_CALC.tif

COJ_Boundary.zip

If you follow the steps exactly, they should reproduce the results as shown. If you still have an issue after using these datasets - attach a screenshot and we will take a look.