Timeline for Quartile calculation option in QGIS?
Current License: CC BY-SA 4.0
6 events
| when toggle format | what | by | license | comment | |
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| Jan 30, 2020 at 12:30 | comment | added | Houska |
@JianZhang, sorry this is exceeding my ability to visualize. However, you could try converting the multipolygons to polygons. And/or dissolving them? GRASS does polygons differently than QGIS ("topologically", as a tiling of the mapping region with no gaps, overlaps etc), so I'd be a bit leery of throwing multipolygons into the mix. And maybe run Fix geometry on the vector layer? Just ideas...
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| Jan 30, 2020 at 5:49 | comment | added | Jian Zhang | Now I have another question. I use "v.rast.stats" to calculate the "third_quartile" for a multipolygon file. I realize that it generates a lot of rows for each species (could be the same length with the occupied raster cells for each species). That makes the results really long, and the size is huge. Is there any way to only generate one row for each species? | |
| Jan 28, 2020 at 16:08 | comment | added | Houska | Good to hear. Be careful about NODATA pixels, if that's relevant. GRASS and native QGIS don't always seamlessly communicate on what are NODATA values and this could throw off quantiles if present in your data set. | |
| Jan 28, 2020 at 15:41 | vote | accept | Jian Zhang | ||
| Jan 28, 2020 at 15:41 | comment | added | Jian Zhang | Thanks. v.rast.stats seems work. I am running that now. | |
| Jan 28, 2020 at 15:19 | history | answered | Houska | CC BY-SA 4.0 |