I'm using the above mentioned QGIS version, and it somehow does not include ZonalStats plugin. I installed ZonalStats 0.0.4, but plugins now says this is designed for QGIS 1.7.2-1.99 and does not work for me. Is there a way to get hold on Zonal Stats?
[GIS] Using ZonalStats in QGIS 3.0.2
qgiszonal statistics
Related Solutions
I have this problem with the 64bit version. Grass 7.0.5 is a recent release, like less than a week. QGIS and the GRASS 7 plugin haven't been updated to catch up - e.g. if you look at the batch file launchers in \bin you'll see they all refer to 7.0.4.
What you need to do is launch the OSGeo4W setup, go to Advanced Install, navigate to the package list, and roll it back to 7.0.4. Until the rest of the package is updated, you should only install 7.0.5 if you're going to use it as a standalone app.
You can also uninstall qgis, qgis-grass-plugin7, qgis-grass-plugin6, qgis-grass-plugin-common and install qgis-rel-dev instead which will also install GRASS 7 because it has the grass plugin bundled up with it.
Then launch QGIS Desktop x.x.x with GRASS x.x.x (Nightly) from the start menu.
This is a nightly build of the release branch for QGIS with current patches and fixes.
QGIS first makes an initial pass, checking to see if the center of each raster cell is within the polygon. If fewer than two cell centers are within the polygon, it performs a vector-based intersection for all intersecting cells, whether their center is within the polygon or not, and computes a weight that is the fraction of each cell that is covered by the polygon. If two or more cell centers are within the polygon, those cells are assigned a weight of 1 and all other cells are assigned a weight of 0.
How these weights are applied depends on the statistic in question.
- The sum is calculated as the sum of each pixel value times its weight.
- The count is calculated as the sum of all pixel weights.
- The mean is calculated as the sum divided by the count.
- The median, variance, standard deviation, minimum, and maximum are calculated for all pixels with a weight > 0, but do not take individual pixel weights into account in the calculations.
Relevant source code:
Best Answer
If you wrote zonal in the Processing toolbox search, you will find many:
The zonal Statistics is the second one from the top.